为啥本地跑飞快,交上去就T捏

#include<bits/stdc++.h>
#include<bits/stdc++.h>
using namespace std;
int a,b;
int res;
int ans;
int main()
{
    cin>>a>>b;
    //a=1;b=2;
    srand(time(0));
    while(res<=100000000)
    {
        res++;
        ans=rand();
        if(ans-a==b)
        {
            cout<<ans;
            return 0;
        }
    }

    return 0;
}

a=1,b=2;

本地:

3
--------------------------------
Process exited after 0.1829 seconds with return value 0
请按任意键继续. . .

洛谷