HDU 3123 GCC

 

GCC

Time Limit: 1000/1000 MS (Java/Others) Memory Limit: 131072/131072 K (Java/Others)
Total Submission(s): 4204 Accepted Submission(s): 1384


Problem Description The GNU Compiler Collection (usually shortened to GCC) is a compiler system produced by the GNU Project supporting various programming languages. But it doesn’t contains the math operator “!”.
In mathematics the symbol represents the factorial operation. The expression n! means "the product of the integers from 1 to n". For example, 4! (read four factorial) is 4 × 3 × 2 × 1 = 24. (0! is defined as 1, which is a neutral element in multiplication, not multiplied by anything.)
We want you to help us with this formation: (0! + 1! + 2! + 3! + 4! + ... + n!)%m

Input The first line consists of an integer T, indicating the number of test cases.
Each test on a single consists of two integer n and m.

Output Output the answer of (0! + 1! + 2! + 3! + 4! + ... + n!)%m.

Constrains
0 < T <= 20
0 <= n < 10^100 (without leading zero)
0 < m < 1000000

Sample Input

1
10 861017

Sample Output

593846

 

n大於m的部分不需要求，取模後等於0了嘛

 

#include 
#include 
#include 
#include 
#include 
#define N 1000009
using namespace std;

char s[N];
int m;

int main()
{
    int ca;

    scanf("%d",&ca);
    while(ca--)
    {
        int ff=0;
        scanf("%s%d",s,&m);

        int len=strlen(s);
        int num=0;

        if(len>=7)
        ff=m;
        else
        {
            for(int i=0;i=m)
            {
                ff=m-1;
            }
            else ff=num;
        }

        __int64 ans=0;
        __int64 t=1;

        for(int i=1;i<=ff;i++)
        {
            t*=i;
            t%=m;
            ans+=t;
            ans%=m;

        }
        ans=(ans+1)%m;//如果開始ans取1後再求mod的話會wa，但是最後加1再取mod就過了

        printf("%I64d\n",ans);

    }
    return 0;
}