Submission #1006172

#	Time	Username	Problem	Language	Result	Execution time	Memory
1006172		Abdullah_Alodaibi	Coins (IOI17_coins)	C++17	Compilation error	0 ms	0 KiB

coins

#include "bits/stdc++.h"
using namespace std;
using ll = long long;
vector<int> coin_flips(vector<int> b, int c){
    int x=0;
    for(int i=0;i<b.size();i++){
        x^=b[i]*i;
        x%=b.size();
    }
    b[x^c]=(b[x^c]+1)%2;
    return b;
}
int find_coin(vector<int> b){
    int x=0;
    for(int i=0;i<b.size();i++){
        x^=b[i]*i;
        x%=b.size();
    }
    return x;
}
int main(){
    ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0);
    ll t;
    cin>>t;
    while(t--){
        vector<int> b;
        int c;
        cin>>c;
        for(int i=0;i<64;i++){
            char x;
            cin>>x;
            b.push_back(int(x)-48);
        }
        cout<<find_coin(coin_flips(b,c))<<"\n";
    }
}

Compilation message (stderr)

coins.cpp: In function 'std::vector<int> coin_flips(std::vector<int>, int)':
coins.cpp:6:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
    6 |     for(int i=0;i<b.size();i++){
      |                 ~^~~~~~~~~
coins.cpp: In function 'int find_coin(std::vector<int>)':
coins.cpp:15:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   15 |     for(int i=0;i<b.size();i++){
      |                 ~^~~~~~~~~
/usr/bin/ld: /tmp/cc0rVS6f.o: in function `main':
grader.cpp:(.text.startup+0x0): multiple definition of `main'; /tmp/ccPFyVJc.o:coins.cpp:(.text.startup+0x0): first defined here
collect2: error: ld returned 1 exit status