Submission #1532163

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Source Code Expand

#include <bits/stdc++.h>
using namespace std;

int main(void)
{
    int N,M;
    cin >> N >> M;
    int a;
    int b;
    bool s[200010] = {false};
    bool t[200010] = {false};

    for( int i = 0; i < M; i++){
        cin >> a >> b;
        if( a == 1 ) s[b] = true;
        if( b == N ) t[a] = true;
    }

    for( int i = 0; i <= M; i++){
        if( s[i] == true && t[i] == true ){
            printf("POSSIBLE");
            return 0;
        }
    }
    printf("IMPOSSIBLE");
    
    return 0;
}

Submission Info

Judge Result