大数取模

//大数取模
#include "cmath"
#include "iostream"
#include "string.h"
using namespace std;

int mod(char str[],int num)
{
    int number[100];
    for(int i=0;i<strlen(str);i++)
     number[i]=str[i]-'0';
    int remainder=0;
    for(int i=0;i<strlen(str);i++)
    {
        remainder=((long long)remainder*10+number[i])%num;
    }
    return remainder;
} 

int main(){
	char ch[10] = {'1','3','\0'};
	cout << mod(ch, 5);
	return 0;
}