题目链接
https://www.nowcoder.com/acm/contest/93/E
思路 其实就是找阶乘的项中5的个数
末尾为什么会出现0 因为存在5的倍数和偶数相乘 有0存在
借鉴 https://blog.csdn.net/tommyzht/article/details/46309563
AC代码
#include <cstdio> #include <cstring> #include <ctype.h> #include <cstdlib> #include <cmath> #include <climits> #include <ctime> #include <iostream> #include <algorithm> #include <deque> #include <vector> #include <queue> #include <string> #include <map> #include <stack> #include <set> #include <numeric> #include <sstream> #include <iomanip> #include <limits> #define CLR(a) memset(a, 0, sizeof(a)) #define pb push_back using namespace std; typedef long long ll; typedef long double ld; typedef unsigned long long ull; typedef pair <int, int> pii; typedef pair <ll, ll> pll; typedef pair<string, int> psi; typedef pair<string, string> pss; const double PI = 3.14159265358979323846264338327; const double E = exp(1); const double eps = 1e-30; const int INF = 0x3f3f3f3f; const int maxn = 1e9 + 5; const int MOD = 1e9 + 7; // //int num[maxn], len; // //void init() //{ // len = 1; // num[0] = 1; //} // //int mult(int num[], int len, int n) //{ // ll tmp = 0; // for (ll i = 0; i < len; i++) // { // tmp = tmp + num[i] * n; // num[i] = tmp % 10; // tmp = tmp / 10; // } // while (tmp) // { // num[len++] = tmp % 10; // tmp = tmp / 10; // } // return len; //} int main() { int T; scanf("%d", &T); while (T--) { //int Num; //scanf("%d", &Num); //init(); //for (int i = 2; i <= Num; i++) //{ // len = mult(num, len, i); //} //int ans = 0; //for (int i = 0; i < len; i++) //{ // if (num[i]) // break; // else // ans++; //} //printf("%d\n", ans); int n; scanf("%d", &n); int ans = 0; for (int i = 5; ; i *= 5) { ans += n / i; if (n / i == 0) break; } printf("%d\n", ans); } }转载于:https://www.cnblogs.com/Dup4/p/9433151.html
