Submission #1970894

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Source Code Expand

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

int par[100001], d[100001], f[100001];
void init(int n){
	for(int i = 1;i <= n;i++){
		par[i] = i;
		d[i] = 0;
	}
}

int find(int x){
	if(x == par[x])return x;
	return par[x] = find(par[x]);
}

void unite(int x, int y){
	x = find(x);
	y = find(y);
	if(x == y)return ;
	if(d[x] < d[y]){
		par[x] = y;
	}else{
		par[y] = x;
		if(d[x] == d[y])d[x]++;
	}
}

bool same(int x, int y){
	return find(x) == find(y);
}

int main(){
	int n, m, x, y;
	scanf("%d%d", &n, &m);
	init(n);
	
	for(int i = 0;i < m;i++){
		scanf("%d%d", &x, &y);
		unite(x, y);
	}
	
	int ans = 0;
	for(int i = 1;i <= n;i++)find(i);
	for(int i = 1;i <= n;i++){
		if(f[find(i)] == 1)continue;
		f[find(i)] = 1;
		unite(i, 1);
		ans++;
	}
	printf("%d\n", ans-1);
	return 0;
}

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:35:23: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d%d", &n, &m);
                       ^
./Main.cpp:39:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d%d", &x, &y);
                        ^

Judge Result