TASK038 Graph_Cycle

#include<iostream>
using namespace std;

typedef struct{
    int parent;
    int rank;
}subset;

int find(int x,subset set[]){
    if(set[x].parent == x){
        return x;
    }
    return set[x].parent = find(set[x].parent,set);
}

void unions(int x,int y,subset set[]){
    int rootx = find(x,set);
    int rooty = find(y,set);

    if(set[rootx].rank > set[rooty].rank){ //x is higher rank
        set[rooty].parent = rootx;
    }
    else if(set[rootx].rank < set[rooty].rank){ //y is higher rank
        set[rootx].parent = rooty;
    }
    else{ //rank x equal rank y
        set[rootx].parent = rooty;
        set[rooty].rank++;
    }
}

int main(){
    int v,e;
    cin>>v>>e;
    subset set[v+1];for(int i=0;i<=v;i++){
        set[i].parent = i;
        set[i].rank = 0;
    }
    bool iscycle = false;
    for(int i=0;i<e;i++){
        int u,v;
        cin>>u>>v;
        if(find(u,set) == find(v,set)){
            iscycle = true;
        }else{
            unions(u,v,set);
        }
    }
    cout<<(iscycle?"Yes":"No");
    return 0;
}