hello, there's something weird happened to me in szkopul website which caused TLE and after small changes to the code, it got AC..it happened to me in 2 problems.

1 — first problem : POI10-sums

I got 90 with this code and got TLE in test case 8 , but after that I got the full score using this code , the only difference between the two codes is that loop in dijkstra which in first code is :

for(int i = 0 ; i < n ; ++i)
{
    int now2 = now + arr[i] ;
    int cur2 = (cur + arr[i]) % arr[0] ;
    if(now2 > 1e9)
        continue ;
    if(now2 < vis[cur2] && now2 <= 1e9)
    {
        vis[cur2] = now2 ;
        q.push({now2 , cur2}) ;
    }
}

but in second code it's :

for(int i = 0 ; i < n ; ++i)
{
    int now2 = now + arr[i] ;
    int cur2 = (cur + arr[i]) % arr[0] ;
    //if(now2 > 1e9)
    //    continue ;
    if(now2 < vis[cur2] && now2 <= 1e9)
    {
        vis[cur2] = now2 ;
        q.push({now2 , cur2}) ;
    }
}

so the only difference is that I put this comment , there's no additional loop or nothing and the condition also was right.

2 — second problem : POI15-seals

I got 56 with this code and got TLE at test case 6, 7, 8, and 9, after that I made a small change and got 100 with this code, the only difference is that I made

char arr[n][m] , arr2[a][b] ;

in the first code , and replaced it with

vector<string>arr(n) ;
vector<string>arr2(a);

in the second code, and I don't think that makes that great difference because it's the same time in taking input.

so I would like to know what makes first codes in this two problems get TLE and after very small differences it got the full score even that these small differences don't affect the time of the codes.

hope the blog wasn't long and hope to know the reason of TLE.

Thanks.