From fa8582030c0fb7a2bc73e53d6dfa650e3debe49d Mon Sep 17 00:00:00 2001
From: Walt Mankowski <waltman@pobox.com>
Date: Tue, 4 Aug 2020 19:22:31 -0400
Subject: C++ code for challenge 72

---
 challenge-072/walt-mankowski/c++/.gitignore |  2 ++
 challenge-072/walt-mankowski/c++/Makefile   | 23 ++++++++++++++++++++++
 challenge-072/walt-mankowski/c++/ch-1.cpp   | 30 +++++++++++++++++++++++++++++
 challenge-072/walt-mankowski/c++/ch-2.cpp   | 29 ++++++++++++++++++++++++++++
 4 files changed, 84 insertions(+)
 create mode 100644 challenge-072/walt-mankowski/c++/.gitignore
 create mode 100644 challenge-072/walt-mankowski/c++/Makefile
 create mode 100644 challenge-072/walt-mankowski/c++/ch-1.cpp
 create mode 100644 challenge-072/walt-mankowski/c++/ch-2.cpp

diff --git a/challenge-072/walt-mankowski/c++/.gitignore b/challenge-072/walt-mankowski/c++/.gitignore
new file mode 100644
index 0000000000..ac77297bfe
--- /dev/null
+++ b/challenge-072/walt-mankowski/c++/.gitignore
@@ -0,0 +1,2 @@
+ch-1
+ch-2
diff --git a/challenge-072/walt-mankowski/c++/Makefile b/challenge-072/walt-mankowski/c++/Makefile
new file mode 100644
index 0000000000..0192513d07
--- /dev/null
+++ b/challenge-072/walt-mankowski/c++/Makefile
@@ -0,0 +1,23 @@
+CPP = /usr/bin/c++
+INCLDIRS =
+LIBDIRS =
+LIBS =
+CFLAGS = -std=c++17 -Wall -O3 $(INCLDIRS)
+OBJECTS1 = ch-1.o
+OBJECTS2 = ch-2.o
+
+all: ch-1 ch-2
+
+%.o: %.cpp
+	$(CPP) $(CFLAGS) -c $<
+
+ch-1: $(OBJECTS1)
+	$(CPP) -o $@ $(OBJECTS1) $(LIBDIRS) $(LIBS)
+
+ch-2: $(OBJECTS2)
+	$(CPP) -o $@ $(OBJECTS2) $(LIBDIRS) $(LIBS)
+
+clean:
+	rm -f *~
+	rm -f *.o
+	rm -f ch-1 ch-2
diff --git a/challenge-072/walt-mankowski/c++/ch-1.cpp b/challenge-072/walt-mankowski/c++/ch-1.cpp
new file mode 100644
index 0000000000..ba8c614fa1
--- /dev/null
+++ b/challenge-072/walt-mankowski/c++/ch-1.cpp
@@ -0,0 +1,30 @@
+#include <stdlib.h>
+#include <iostream>
+#include <string>
+
+using namespace std;
+
+const unsigned long long fact(const int n) {
+    unsigned long long res = 1;
+    for (int i = 2; i <= n; i++)
+        res *= i;
+    return res;
+}
+
+const int num_trailing_zeros(const unsigned long long n) {
+    int cnt = 0;
+    unsigned long long pwr = 10;
+    while (n % pwr == 0) {
+        cnt++;
+        pwr *= 10;
+    }
+    return cnt;
+}
+
+int main(int argc, char *argv[]) {
+    int n = atoi(argv[1]);
+    unsigned long long f = fact(n);
+    int z = num_trailing_zeros(f);
+    string zeros = (z == 1) ? "zero" : "zeros";
+    cout << n << " as N! = " << f << " has " << z << " trailing " << zeros << endl;
+}
diff --git a/challenge-072/walt-mankowski/c++/ch-2.cpp b/challenge-072/walt-mankowski/c++/ch-2.cpp
new file mode 100644
index 0000000000..03f5d1c067
--- /dev/null
+++ b/challenge-072/walt-mankowski/c++/ch-2.cpp
@@ -0,0 +1,29 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <iostream>
+#include <fstream>
+#include <string>
+
+using namespace std;
+
+int main(int argc, char *argv[]) {
+    const string fname = argv[1];
+    const int a = atoi(argv[2]);
+    const int b = atoi(argv[3]);
+
+    ifstream infile(fname);
+    if (!infile) {
+        perror(fname.c_str());
+        exit(1);
+    }
+
+    int lineno = 1;
+    string s;
+    while (infile >> s) {
+        if (a <= lineno && lineno <= b)
+            cout << s << endl;
+        lineno++;
+        if (lineno > b)
+            break;
+    }
+}
-- 
cgit