Add Awk, C, C++ and Python solutions to challenge 100

2 files changed, 230 insertions, 0 deletions

diff --git a/challenge-100/paulo-custodio/cpp/ch-1.cpp b/challenge-100/paulo-custodio/cpp/ch-1.cpp
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+++ b/challenge-100/paulo-custodio/cpp/ch-1.cpp
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+/*
+TASK #1 > Fun Time
+Submitted by: Mohammad S Anwar
+You are given a time (12 hour / 24 hour).
+
+Write a script to convert the given time from 12 hour format to 24 hour format
+and vice versa.
+
+Ideally we expect a one-liner.
+
+Example 1:
+Input: 05:15 pm or 05:15pm
+Output: 17:15
+Example 2:
+Input: 19:15
+Output: 07:15 pm or 07:15pm
+*/
+
+#include <iostream>
+#include <iomanip>
+#include <sstream>
+#include <cctype>
+
+class Time {
+public:
+    Time(int hours = 0, int minutes = 0)
+        : m_hours(hours), m_minutes(minutes), m_is12(false) {}
+
+    int hours() const { return m_hours; }
+    int minutes() const { return m_minutes; }
+    bool is12() const { return m_is12; }
+    void set12() { m_is12 = true; }
+    void set24() { m_is12 = false; }
+
+    friend std::ostream& operator<<(std::ostream& os, const Time& time);
+    friend std::istream& operator>>(std::istream& is, Time& time);
+
+private:
+    int m_hours, m_minutes; // always in 24 hour format
+    bool m_is12;
+};
+
+std::ostream& operator<<(std::ostream& os, const Time& time) {
+    if (time.m_is12) {
+        int hours = time.m_hours;
+        bool ispm = false;
+        if (hours == 0)
+            hours = 12;
+        else if (hours == 12)
+            ispm = true;
+        else if (hours > 12) {
+            ispm = true;
+            hours -= 12;
+        }
+        os << std::setw(2) << std::setfill('0') << hours << ":"
+            << std::setw(2) << std::setfill('0') << time.m_minutes
+            << (ispm ? "pm" : "am");
+    }
+    else
+        os << std::setw(2) << std::setfill('0') << time.m_hours << ":"
+        << std::setw(2) << std::setfill('0') << time.m_minutes;
+    return os;
+}
+
+std::istream& operator>>(std::istream& is, Time& time) {
+    // get hh:mm
+    char colon = '\0';
+    if (!(is >> time.m_hours >> colon >> time.m_minutes) || colon != ':') {
+        std::cerr << "error parsing time" << std::endl;
+        exit(EXIT_FAILURE);
+    }
+
+    // get optional am|pm
+    std::string ampm;
+    is >> ampm; 
+
+    // convert from 12 to 24 format
+    if (!ampm.empty()) {
+        switch (tolower(ampm[0])) {
+        case 'a':
+            if (time.m_hours == 12) time.m_hours = 0;
+            time.m_is12 = true;
+            break;
+        case 'p':
+            if (time.m_hours != 12) time.m_hours += 12;
+            time.m_is12 = true;
+            break;
+        default:
+            std::cerr << "error parsing time" << std::endl;
+            exit(EXIT_FAILURE);
+        }
+    }
+    return is;
+}
+
+
+int main(int argc, char* argv[]) {
+    if (argc != 2) {
+        fputs("Usage: ch-1 time", stderr);
+        return EXIT_FAILURE;
+    }
+
+    Time time;
+    std::stringstream ss(argv[1]);
+    ss >> time;
+    if (time.is12())
+        time.set24();
+    else
+        time.set12();
+    std::cout << time << std::endl;
+}
diff --git a/challenge-100/paulo-custodio/cpp/ch-2.cpp b/challenge-100/paulo-custodio/cpp/ch-2.cpp
new file mode 100644
index 0000000000..b672a5cffe
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+++ b/challenge-100/paulo-custodio/cpp/ch-2.cpp
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+/*
+TASK #2 > Triangle Sum
+Submitted by: Mohammad S Anwar
+You are given triangle array.
+
+Write a script to find the minimum path sum from top to bottom.
+
+When you are on index i on the current row then you may move to either
+index i or index i + 1 on the next row.
+
+Example 1:
+Input: Triangle = [ [1], [2,4], [6,4,9], [5,1,7,2] ]
+Output: 8
+
+Explanation: The given triangle
+
+            1
+           2 4
+          6 4 9
+         5 1 7 2
+
+The minimum path sum from top to bottom:  1 + 2 + 4 + 1 = 8
+
+             [1]
+           [2]  4
+           6 [4] 9
+          5 [1] 7 2
+Example 2:
+Input: Triangle = [ [3], [3,1], [5,2,3], [4,3,1,3] ]
+Output: 7
+
+Explanation: The given triangle
+
+            3
+           3 1
+          5 2 3
+         4 3 1 3
+
+The minimum path sum from top to bottom: 3 + 1 + 2 + 1 = 7
+
+             [3]
+            3  [1]
+           5 [2] 3
+          4 3 [1] 3
+*/
+
+#include <iostream>
+#include <vector>
+#include <cassert>
+#include <cctype>
+
+#define MIN(a,b)    ((a)<(b)?(a):(b))
+
+// triangle (stored as a square)
+class Triangle {
+public:
+    bool parse(int argc, char* argv[]) {
+        for (int row = 0; row < argc; row++) {
+            add_row();
+            if (!parse_row(row, argv[row]))
+                return false;
+        }
+        return true;
+    }
+
+    int min_sum() {
+        return min_sum_1(0, 0, 0);
+    }
+
+private:
+    std::vector<std::vector<int>> m_data;
+
+    void add_row() {
+        int rows = static_cast<int>(m_data.size()) + 1;
+        m_data.resize(rows);
+        for (int i = 0; i < rows; i++)
+            m_data[i].resize(rows);
+    }
+
+    bool parse_row(int row, const char* text) {
+        int rows = static_cast<int>(m_data.size());
+        assert(row >= 0 && row < rows);
+        for (int i = 0; i < rows; i++) {
+            while (*text && !isdigit(*text)) text++;
+            if (!isdigit(*text))
+                return false;
+            m_data[row][i] = atoi(text);
+            while (*text && isdigit(*text)) text++;
+        }
+        return true;
+    }
+
+    int min_sum_1(int sum, int row, int col) {
+        sum += m_data[row][col];
+        int rows = static_cast<int>(m_data.size());
+        if (row + 1 == rows)
+            return sum;
+        else {
+            int sum1 = min_sum_1(sum, row + 1, col);
+            int sum2 = min_sum_1(sum, row + 1, col + 1);
+            return MIN(sum1, sum2);
+        }
+    }
+};
+
+int main(int argc, char* argv[]) {
+    if (argc == 1) {
+        fputs("Usage: ch-2 row row ...", stderr);
+        return EXIT_FAILURE;
+    }
+    argc--; argv++;
+    Triangle triangle;
+    if (!triangle.parse(argc, argv)) {
+        fputs("Malformed triangle", stderr);
+        return EXIT_FAILURE;
+    }
+    int sum = triangle.min_sum();
+    std::cout << sum << std::endl;
+}