Submission #405873

#	Time	Username	Problem	Language	Result	Execution time	Memory
405873		jk410	Sorting (IOI15_sorting)	C++17	Compilation error	0 ms	0 KiB

sorting

#include <iostream>
#include <vector>
using namespace std;
int N,M;
int S[500],T[500],R[500];
bool Visited[500];
vector<pair<int,int>> SwapPair,Ans;
bool f(int k){
    Ans.clear();
    for (int i=0; i<N; i++){
        T[i]=S[i];
        Visited[i]=0;
    }
    for (int i=0; i<k; i++)
        swap(T[SwapPair[i].first],T[SwapPair[i].second]);
    for (int i=0; i<N; i++){
        if (T[i]!=i&&!Visited[i]){
            Visited[i]=true;
            for (int j=T[i]; !Visited[j]; j=T[j]){
                Visited[j]=true;
                Ans.push_back({j,T[j]});
            }
        }
    }
    if (Ans.size()>k)
        return false;
    while (Ans.size()!=k)
        Ans.push_back({0,0});
    return true;
}
int main(){
    ios::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    cin>>N;
    for (int i=0; i<N; i++){
        cin>>S[i];
        R[S[i]]=i;
    }
    cin>>M;
    for (int j=0; j<M; j++){
        int x,y;
        cin>>x>>y;
        SwapPair.push_back({x,y});
    }
    for (int i=0; i<=N; i++){
        if (f(i))
            break;
    }
    cout<<Ans.size();
    for (int i=0; i<Ans.size(); i++){
        swap(R[S[SwapPair[i].first]],R[S[SwapPair[i].second]]);
        swap(S[SwapPair[i].first],S[SwapPair[i].second]);
        cout<<"\n"<<R[Ans[i].first]<<" "<<R[Ans[i].second];
        swap(S[R[Ans[i].first]],S[R[Ans[i].second]]);
        swap(R[Ans[i].first],R[Ans[i].second]);
    }
    return 0;
}

Compilation message (stderr)

sorting.cpp: In function 'bool f(int)':
sorting.cpp:25:19: warning: comparison of integer expressions of different signedness: 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   25 |     if (Ans.size()>k)
      |         ~~~~~~~~~~^~
sorting.cpp:27:22: warning: comparison of integer expressions of different signedness: 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   27 |     while (Ans.size()!=k)
      |            ~~~~~~~~~~^~~
sorting.cpp: In function 'int main()':
sorting.cpp:51:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   51 |     for (int i=0; i<Ans.size(); i++){
      |                   ~^~~~~~~~~~~
/usr/bin/ld: /tmp/ccklLoIt.o: in function `main':
grader.c:(.text.startup+0x0): multiple definition of `main'; /tmp/cc5k7Fpw.o:sorting.cpp:(.text.startup+0x0): first defined here
/usr/bin/ld: /tmp/ccklLoIt.o: in function `main':
grader.c:(.text.startup+0x4eb): undefined reference to `findSwapPairs(int, int*, int, int*, int*, int*, int*)'
collect2: error: ld returned 1 exit status