Add C and C++ solutions

6 files changed, 561 insertions, 69 deletions

diff --git a/challenge-209/paulo-custodio/basic/ch-1.bas b/challenge-209/paulo-custodio/basic/ch-1.bas
index fb9a6300d9..f3b1c1013f 100644
--- a/challenge-209/paulo-custodio/basic/ch-1.bas
+++ b/challenge-209/paulo-custodio/basic/ch-1.bas
@@ -29,23 +29,23 @@
 ' (10) i.e. the last character is not 1-bit character.
 
 function decode(in as string) as string
-	dim result as string
-	do while in<>""
-		if left(in,1)="0" then
-			result=result+"a"
-			in=mid(in,2)
-		elseif left(in,2)="10" then
-			result=result+"b"
-			in=mid(in,3)
-		elseif left(in,2)="11" then
-			result=result+"c"
-			in=mid(in,3)
-		else 
-			print "Error: cannot parse: "; in
-			end
-		end if
-	loop
-	decode=result
+    dim result as string
+    do while in<>""
+        if left(in,1)="0" then
+            result=result+"a"
+            in=mid(in,2)
+        elseif left(in,2)="10" then
+            result=result+"b"
+            in=mid(in,3)
+        elseif left(in,2)="11" then
+            result=result+"c"
+            in=mid(in,3)
+        else
+            print "Error: cannot parse: "; in
+            end
+        end if
+    loop
+    decode=result
 end function
 
 dim in as string, result as string
diff --git a/challenge-209/paulo-custodio/basic/ch-2.bas b/challenge-209/paulo-custodio/basic/ch-2.bas
index 96447e2b53..02e2fb621f 100644
--- a/challenge-209/paulo-custodio/basic/ch-2.bas
+++ b/challenge-209/paulo-custodio/basic/ch-2.bas
@@ -33,68 +33,108 @@ dim shared names() as string
 dim shared emails() as string
 
 sub collect_args()
-	dim i as integer, j as integer, row as integer
-	row=1
-	i=1
-	do while command(i)<>""
-		redim preserve names(row) as string
-		redim preserve emails(row) as string
-		names(row)=command(i)
-		i=i+1
-		do while command(i)<>"" and command(i)<>","
-			emails(row)=emails(row)+command(i)+" "
-			i=i+1
-		loop
-		if command(i)="," then i=i+1: row=row+1
-	loop
+    dim i as integer, j as integer, row as integer
+    row=1
+    i=1
+    do while command(i)<>""
+        redim preserve names(row) as string
+        redim preserve emails(row) as string
+        names(row)=command(i)
+        i=i+1
+        do while command(i)<>"" and command(i)<>","
+            emails(row)=emails(row)+command(i)+" "
+            i=i+1
+        loop
+        if command(i)="," then i=i+1: row=row+1
+    loop
 end sub
 
 sub split(byval text as string, delim as string = " ", ret() as string)
-	dim p as integer, count as integer
-	count=0
-	do
-		do while left(text,1)=delim: text=mid(text,2): loop	' eat front delimiters
-		if text="" then exit do
-		redim preserve ret(count) as string
-		p=instr(text,delim)
-		if p<1 then
-			ret(count)=text
-			exit do
-		else
-			ret(count)=left(text,p-1)
-			text=mid(text,p+1)
-			count=count+1
-		end if
-	loop
+    dim p as integer, count as integer
+    count=0
+    do
+        do while left(text,1)=delim: text=mid(text,2): loop ' eat front delimiters
+        if text="" then exit do
+        redim preserve ret(count) as string
+        p=instr(text,delim)
+        if p<1 then
+            ret(count)=text
+            exit do
+        else
+            ret(count)=left(text,p-1)
+            text=mid(text,p+1)
+            count=count+1
+        end if
+    loop
 end sub
 
 function common_email(byref aa as integer, byref bb as integer) as boolean
-	dim emails_a() as string, emails_b() as string
-	dim a as integer, i as integer, b as integer, j as integer
-	for a=0 to ubound(names)
-		split(emails(a),,emails_a())
-		for i=0 to ubound(emails_a)
-			for b=0 to ubound(names)
-				if a<>b then
-					split(emails(b),,emails_b())
-					for j=0 to ubound(emails_b)
-						if mails_a(i)=mails_b(j) then
-							aa=a: bb=b: common_email=true
-							exit function
-						end if
-					next
-				end if
-			next
-		next
-	next
-	common_email=false
+    dim emails_a() as string, emails_b() as string
+    dim a as integer, i as integer, b as integer, j as integer
+    for a=0 to ubound(names)
+        split(emails(a),,emails_a())
+        for i=0 to ubound(emails_a)
+            for b=0 to ubound(names)
+                if a<>b then
+                    split(emails(b),,emails_b())
+                    for j=0 to ubound(emails_b)
+                        if emails_a(i)=emails_b(j) then
+                            aa=a: bb=b: common_email=true
+                            exit function
+                        end if
+                    next
+                end if
+            next
+        next
+    next
+    common_email=false
 end function
 
+sub sort(s() as string)
+    dim i as integer, j as integer, tmp as string
+    for i=0 to ubound(s)-1
+        for j=i+1 to ubound(s)
+            if s(i)>s(j) then tmp=s(i): s(i)=s(j): s(j)=tmp
+        next
+    next
+end sub
+
+function sort_uniq_emails(emails as string) as string
+    dim s() as string, i as integer, last as string, ret as string
+    split emails,,s()
+    sort s()
+    ret=""
+    for i=0 to ubound(s)
+        if s(i)<>last then
+            ret=ret+s(i)+" "
+            last=s(i)
+        end if
+    next
+    sort_uniq_emails=ret
+end function
 
-dim i as integer, a as integer, b as integer
+sub merge_account(a as integer, b as integer)
+    dim all_emails as string, i as integer
+    all_emails=sort_uniq_emails(emails(a)+" "+emails(b))
+    emails(a)=all_emails
+    for i=b to ubound(names)-1
+        names(i)=names(i+1)
+        emails(i)=emails(i+1)
+    next
+    redim preserve names(ubound(names)-1)
+    redim preserve emails(ubound(emails)-1)
+end sub
+
+sub merge_accounts()
+    dim a as integer, b as integer
+    do while common_email(a, b)
+        merge_account(a, b)
+    loop
+end sub
 
+dim i as integer
 collect_args
-if common_email(a, b) then print a, b
+merge_accounts
 for i=0 to ubound(names)
-	print i;names(i) ',emails(i)
+    print names(i);" ";emails(i)
 next
diff --git a/challenge-209/paulo-custodio/c/ch-1.c b/challenge-209/paulo-custodio/c/ch-1.c
new file mode 100644
index 0000000000..370f5f0399
--- /dev/null
+++ b/challenge-209/paulo-custodio/c/ch-1.c
@@ -0,0 +1,69 @@
+/*
+Challenge 209
+
+Task 1: Special Bit Characters
+Submitted by: Mohammad S Anwar
+
+You are given an array of binary bits that ends with 0.
+
+Valid sequences in the bit string are:
+
+[0] -decodes-to-> "a"
+[1, 0] -> "b"
+[1, 1] -> "c"
+
+Write a script to print 1 if the last character is an “a” otherwise print 0.
+Example 1
+
+Input: @bits = (1, 0, 0)
+Output: 1
+
+The given array bits can be decoded as 2-bits character (10) followed by
+1-bit character (0).
+
+Example 2
+
+Input: @bits = (1, 1, 1, 0)
+Output: 0
+
+Possible decode can be 2-bits character (11) followed by 2-bits character
+(10) i.e. the last character is not 1-bit character.
+*/
+
+#define MAX_STRING  256
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+void decode(char* out, const char* in) {
+    const char* p = in;
+    char* q = out;
+    while (*p) {
+        switch (*p) {
+        case '0': *q++ = 'a'; p++; break;
+        case '1':
+            p++;
+            switch (*p) {
+            case '0': *q++ = 'b'; p++; break;
+            case '1': *q++ = 'c'; p++; break;
+            default: fputs("invalid input", stderr); exit(EXIT_FAILURE);
+            }
+            break;
+        default: fputs("invalid input", stderr); exit(EXIT_FAILURE);
+        }
+    }
+    *q++ = '\0';
+}
+
+int main(int argc, char* argv[]) {
+    argv++; argc--;
+    if (argc != 1) {
+        fputs("usage: ch-2 str\n", stderr);
+        return EXIT_FAILURE;
+    }
+
+    char out[MAX_STRING];
+    decode(out, argv[0]);
+    printf("%d\n", out[strlen(out)-1] == 'a' ? 1 : 0);
+}
diff --git a/challenge-209/paulo-custodio/c/ch-2.c b/challenge-209/paulo-custodio/c/ch-2.c
new file mode 100644
index 0000000000..a5349dac18
--- /dev/null
+++ b/challenge-209/paulo-custodio/c/ch-2.c
@@ -0,0 +1,216 @@
+/*
+Challenge 209
+
+Task 2: Merge Account
+Submitted by: Mohammad S Anwar
+
+You are given an array of accounts i.e. name with list of email addresses.
+
+Write a script to merge the accounts where possible. The accounts can only
+be merged if they have at least one email address in common.
+
+Example 1:
+
+Input: @accounts = [ ["A", "a1@a.com", "a2@a.com"],
+                     ["B", "b1@b.com"],
+                     ["A", "a3@a.com", "a1@a.com"] ]
+                   ]
+
+Output: [ ["A", "a1@a.com", "a2@a.com", "a3@a.com"],
+          ["B", "b1@b.com"] ]
+
+Example 2:
+
+Input: @accounts = [ ["A", "a1@a.com", "a2@a.com"],
+                     ["B", "b1@b.com"],
+                     ["A", "a3@a.com"],
+                     ["B", "b2@b.com", "b1@b.com"] ]
+
+Output: [ ["A", "a1@a.com", "a2@a.com"],
+          ["A", "a3@a.com"],
+          ["B", "b1@b.com", "b2@b.com"] ]
+*/
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdbool.h>
+
+typedef struct ArrayStr {
+    int count;
+    char** items;
+} ArrayStr;
+
+typedef struct Account {
+    char* name;
+    ArrayStr* emails;
+} Account;
+
+typedef struct Accounts {
+    int count;
+    Account** items;
+} Accounts;
+
+void* check_mem(void* p) {
+    if (!p) {
+        fputs("Out of memory", stderr);
+        exit(EXIT_FAILURE);
+    }
+    return p;
+}
+
+ArrayStr* arrstr_new() {
+    return check_mem(calloc(1, sizeof(ArrayStr)));
+}
+
+void arrstr_clear(ArrayStr* as) {
+    for (int i = 0; i < as->count; i++)
+        free(as->items[i]);
+    as->count = 0;
+}
+
+void arrstr_free(ArrayStr* as) {
+    arrstr_clear(as);
+    free(as);
+}
+
+void arrstr_push(ArrayStr* as, const char* s) {
+    as->items = check_mem(realloc(as->items, (as->count + 1) * sizeof(char**)));
+    as->items[as->count++] = check_mem(strdup(s));
+}
+
+void arrstr_remove(ArrayStr* as, int idx) {
+    if (idx < as->count) {
+        free(as->items[idx]);
+        memmove(&as->items[idx], &as->items[idx + 1], (as->count - idx - 1) * sizeof(char**));
+        as->count--;
+    }
+}
+
+int compare(const void* a, const void* b) {
+    return strcmp(*(const char**)a, *(const char**)b);
+}
+
+void arrstr_sort(ArrayStr* as) {
+    qsort(as->items, as->count, sizeof(char**), compare);
+}
+
+void arrstr_uniq(ArrayStr* as) {
+    arrstr_sort(as);
+    for (int i = 0; i < as->count - 1; i++) {
+        if (strcmp(as->items[i], as->items[i + 1]) == 0) {
+            arrstr_remove(as, i + 1);
+            i--;
+        }
+    }
+}
+
+int arrstr_find(ArrayStr* as, const char* name) {
+    for (int i = 0; i < as->count; i++)
+        if (strcmp(as->items[i], name) == 0)
+            return i;
+    return -1;
+}
+
+Account* acc_new(const char* name) {
+    Account* acc = check_mem(calloc(1, sizeof(Account)));
+    acc->name = check_mem(strdup(name));
+    acc->emails = arrstr_new();
+    return acc;
+}
+
+void acc_free(Account* acc) {
+    free(acc->name);
+    arrstr_free(acc->emails);
+    free(acc);
+}
+
+void acc_push_email(Account* acc, const char* email) {
+    arrstr_push(acc->emails, email);
+}
+
+void acc_merge(Account* acc, Account* other) {
+    for (int i = 0; i < other->emails->count; i++)
+        acc_push_email(acc, other->emails->items[i]);
+    arrstr_uniq(acc->emails);
+}
+
+Accounts* accs_new() {
+    return check_mem(calloc(1, sizeof(Accounts)));
+}
+
+void accs_clear(Accounts* accs) {
+    for (int i = 0; i < accs->count; i++)
+        acc_free(accs->items[i]);
+    accs->count = 0;
+}
+
+void accs_free(Accounts* accs) {
+    accs_clear(accs);
+    free(accs);
+}
+
+void accs_push(Accounts* accs, const char* name) {
+    accs->items = check_mem(realloc(accs->items, (accs->count + 1) * sizeof(Account**)));
+    accs->items[accs->count++] = acc_new(name);
+}
+
+void accs_remove(Accounts* accs, int idx) {
+    if (idx < accs->count) {
+        acc_free(accs->items[idx]);
+        memmove(&accs->items[idx], &accs->items[idx + 1], (accs->count - idx - 1) * sizeof(Account**));
+        accs->count--;
+    }
+}
+
+bool accs_find_common(Accounts* accs, int* pa, int* pb) {
+    for (*pa = 0; *pa < accs->count - 1; (*pa)++) {
+        for (int i = 0; i < accs->items[*pa]->emails->count; i++) {
+            const char* email = accs->items[*pa]->emails->items[i];
+            for (*pb = *pa + 1; *pb < accs->count; (*pb)++) {
+                if (arrstr_find(accs->items[*pb]->emails, email) >= 0) {
+                    return true;
+                }
+            }
+        }
+    }
+    return false;
+}
+
+void accs_merge(Accounts* accs) {
+    int a, b;
+    while (accs_find_common(accs, &a, &b)) {
+        acc_merge(accs->items[a], accs->items[b]);
+        accs_remove(accs, b);
+    }
+}
+
+int main(int argc, char* argv[]) {
+    argv++; argc--;
+    if (argc == 0) {
+        fputs("usage: name emails... name emails...\n", stderr);
+        return EXIT_FAILURE;
+    }
+
+    Accounts* accs = accs_new();
+
+    for (int i = 0; i < argc; i++) {
+        const char* name = argv[i++];
+        accs_push(accs, name);
+        for (; i < argc && strcmp(argv[i], ",") != 0; i++) {
+            const char* email = argv[i];
+            acc_push_email(accs->items[accs->count - 1], email);
+        }
+    }
+
+    accs_merge(accs);
+
+    for (int i = 0; i < accs->count; i++) {
+        printf("%s ", accs->items[i]->name);
+        for (int j = 0; j < accs->items[i]->emails->count; j++)
+            printf("%s ", accs->items[i]->emails->items[j]);
+        printf("\n");
+    }
+
+    accs_free(accs);
+}
diff --git a/challenge-209/paulo-custodio/cpp/ch-1.cpp b/challenge-209/paulo-custodio/cpp/ch-1.cpp
new file mode 100644
index 0000000000..af0e604c5e
--- /dev/null
+++ b/challenge-209/paulo-custodio/cpp/ch-1.cpp
@@ -0,0 +1,66 @@
+/*
+Challenge 209
+
+Task 1: Special Bit Characters
+Submitted by: Mohammad S Anwar
+
+You are given an array of binary bits that ends with 0.
+
+Valid sequences in the bit string are:
+
+[0] -decodes-to-> "a"
+[1, 0] -> "b"
+[1, 1] -> "c"
+
+Write a script to print 1 if the last character is an “a” otherwise print 0.
+Example 1
+
+Input: @bits = (1, 0, 0)
+Output: 1
+
+The given array bits can be decoded as 2-bits character (10) followed by
+1-bit character (0).
+
+Example 2
+
+Input: @bits = (1, 1, 1, 0)
+Output: 0
+
+Possible decode can be 2-bits character (11) followed by 2-bits character
+(10) i.e. the last character is not 1-bit character.
+*/
+
+#include <iostream>
+#include <string>
+
+std::string decode(const std::string& in) {
+    std::string out;
+    const char* p = in.c_str();
+    while (*p) {
+        switch (*p) {
+        case '0': out.push_back('a'); p++; break;
+        case '1':
+            p++;
+            switch (*p) {
+            case '0': out.push_back('b'); p++; break;
+            case '1': out.push_back('c'); p++; break;
+            default: std::cerr << "invalid input" << std::endl; exit(EXIT_FAILURE);
+            }
+            break;
+        default: std::cerr << "invalid input" << std::endl; exit(EXIT_FAILURE);
+        }
+    }
+    return out;
+}
+
+int main(int argc, char* argv[]) {
+    argv++; argc--;
+    if (argc != 1) {
+        std::cerr << "usage: ch-2 str" << std::endl;
+        return EXIT_FAILURE;
+    }
+
+    std::string out = decode(argv[0]);
+    int result = (!out.empty() && out.back()=='a') ? 1 : 0;
+    std::cout << result << std::endl;
+}
diff --git a/challenge-209/paulo-custodio/cpp/ch-2.cpp b/challenge-209/paulo-custodio/cpp/ch-2.cpp
new file mode 100644
index 0000000000..0767787b2d
--- /dev/null
+++ b/challenge-209/paulo-custodio/cpp/ch-2.cpp
@@ -0,0 +1,101 @@
+/*
+Challenge 209
+
+Task 2: Merge Account
+Submitted by: Mohammad S Anwar
+
+You are given an array of accounts i.e. name with list of email addresses.
+
+Write a script to merge the accounts where possible. The accounts can only
+be merged if they have at least one email address in common.
+
+Example 1:
+
+Input: @accounts = [ ["A", "a1@a.com", "a2@a.com"],
+                     ["B", "b1@b.com"],
+                     ["A", "a3@a.com", "a1@a.com"] ]
+                   ]
+
+Output: [ ["A", "a1@a.com", "a2@a.com", "a3@a.com"],
+          ["B", "b1@b.com"] ]
+
+Example 2:
+
+Input: @accounts = [ ["A", "a1@a.com", "a2@a.com"],
+                     ["B", "b1@b.com"],
+                     ["A", "a3@a.com"],
+                     ["B", "b2@b.com", "b1@b.com"] ]
+
+Output: [ ["A", "a1@a.com", "a2@a.com"],
+          ["A", "a3@a.com"],
+          ["B", "b1@b.com", "b2@b.com"] ]
+*/
+
+#include <algorithm>
+#include <iostream>
+#include <string>
+#include <vector>
+
+struct Account {
+    std::string name;
+    std::vector<std::string> emails;
+
+    Account(const std::string& name_) : name(name_) {}
+
+    void merge(const Account& other) {
+        emails.insert(emails.end(), other.emails.begin(), other.emails.end());  // concatenate
+        std::sort(emails.begin(), emails.end());                                // sort
+        auto it = std::unique(emails.begin(), emails.end());                    // uniq
+        emails.resize(std::distance(emails.begin(), it));
+    }
+};
+
+bool find_common(std::vector<Account>& accs, size_t& a, size_t& b) {
+    for (a = 0; a < accs.size() - 1; a++) {
+        for (size_t i = 0; i < accs[a].emails.size(); i++) {
+            std::string& email = accs[a].emails[i];
+            for (b = a + 1; b < accs.size(); b++) {
+                auto it = std::find(accs[b].emails.begin(), accs[b].emails.end(), email);
+                if (it != accs[b].emails.end())
+                    return true;
+            }
+        }
+    }
+    return false;
+}
+
+void merge_accounts(std::vector<Account>& accs) {
+    size_t a, b;
+    while (find_common(accs, a, b)) {
+        accs[a].merge(accs[b]);
+        accs.erase(accs.begin() + b);
+    }
+}
+
+int main(int argc, char* argv[]) {
+    argv++; argc--;
+    if (argc == 0) {
+        std::cerr << "usage: name emails... name emails..." << std::endl;
+        return EXIT_FAILURE;
+    }
+
+    std::vector<Account> accs;
+
+    for (int i = 0; i < argc; i++) {
+        std::string name = argv[i++];
+        accs.emplace_back(name);
+        for (; i < argc && std::string(argv[i])!= ","; i++) {
+            std::string email = argv[i];
+            accs.back().emails.push_back(email);
+        }
+    }
+
+    merge_accounts(accs);
+
+    for (size_t i = 0; i < accs.size(); i++) {
+        std::cout << accs[i].name << " ";
+        for (size_t j = 0; j < accs[i].emails.size(); j++)
+            std::cout << accs[i].emails[j] << " ";
+        std::cout << std::endl;
+    }
+}