cses

commit d5c06c689e3328546cd4c486b30a7909651501ed
parent 19bb82f44e8da0ab854f93248a8fe72d430b46e4
Author: Jack Sangdahl <jack@pngu.org>
Date:   Thu, 13 Feb 2025 15:18:28 -0700

1618. trailing zeors

Diffstat:
M
introductory_problems/readme.md
 | 
7
+++++++
A
introductory_problems/trailing_zeros.cpp
 | 
13
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2 files changed, 20 insertions(+), 0 deletions(-)
diff --git a/introductory_problems/readme.md b/introductory_problems/readme.md
@@ -62,3 +62,10 @@ Your task is to calculate the number of bit strings of length `n`. For example, 
 **Input**: The only input line has an integer `n`. (Example: 3)
 
 **Output**: Print the result modulo 10E9 + 7. (Example: 8)
+
+### Trailing Zeros
+Your task is to calculate the number of trailing zeros in the factorial `n!`. For example, `20! = 20!=2432902008176640000` and it has 4 trailing zeros.
+
+**Input**: The only input line has an integer `n`. (Example: 20)
+
+**Output**: Print the number of in `n!`. (Example: 4)
diff --git a/introductory_problems/trailing_zeros.cpp b/introductory_problems/trailing_zeros.cpp
@@ -0,0 +1,13 @@
+// 1618. Trailing Zeros
+#include <bits/stdc++.h>
+using namespace std;
+
+int main() {
+  static int n, ans;
+  scanf("%d", &n);
+  while (n) {
+    n /= 5;
+    ans += n;
+  }
+  printf("%d\n", ans);
+}