Atcoder 2332 Training Camp

题目链接：http://abc055.contest.atcoder.jp/tasks/abc055_b?lang=en

B - Training Camp

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Time limit : 2sec / Memory limit : 256MB

Score : 200 points

Problem Statement

Snuke loves working out. He is now exercising N times.

Before he starts exercising, his power is 1. After he exercises for the i-th time, his power gets multiplied by i.

Find Snuke's power after he exercises N times. Since the answer can be extremely large, print the answer modulo 109+7.

Constraints

1≤N≤105

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Input

The input is given from Standard Input in the following format:

N

Output

Print the answer modulo 109+7.

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Sample Input 1

Copy 3

Sample Output 1

Copy 6 After Snuke exercises for the first time, his power gets multiplied by 1 and becomes 1.After Snuke exercises for the second time, his power gets multiplied by 2 and becomes 2.After Snuke exercises for the third time, his power gets multiplied by 3 and becomes 6.

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Sample Input 2

Copy 10

Sample Output 2

Copy 3628800

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Sample Input 3

Copy 100000

Sample Output 3

Copy 457992974

Print the answer modulo 109+7.

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Submit

题意：求n！(9+7)

解析：直接long long，求下n!，每次乘时%mod即可

代码：

#include<iostream> #include<algorithm> #include<cstdio> #include<cstring> #include<vector> #include<queue> #include<map> #include<cmath> #define N 1009 using namespace std; const int INF = 0x3f3f3f3f; typedef unsigned long long LL; const int mod = 1e9 + 7; int main() { LL ans = 1; int n; scanf("%d", &n); for(LL i = 1; i <= n; i++) ans = (ans % mod) * (i % mod) % mod; cout << ans << endl; return 0; }