C++ 比大小

//输入两个可能有前导 0 的大整数，a,b请输出他们谁大谁小#include <iostream>
#include <string>
#include <string.h>
using namespace std;
#define M 100005
int main()
{char a[M], b[M];char *pa, *pb;pa = a;pb = b;cin >> a >> b;while(*pa == '0')pa++;while(*pb == '0')pb++;if(strlen(pa) > strlen(pb)){cout<<"first"<<endl;}else if(strlen(pa) < strlen(pb)){cout<<"second"<<endl;}else{int res = strcmp(pa, pb);if(res > 0){cout<<"first"<<endl;}else if(res < 0){cout<<"second"<<endl;}else{cout<<"same"<<endl;}}return 0;
}