Submission #3878965

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Source Code Expand

#include <stdio.h>  
#include <algorithm>  
#include <assert.h>
#include <bitset>
#include <cmath>  
#include <complex>  
#include <deque>  
#include <functional>  
#include <iostream>  
#include <limits.h>  
#include <map>  
#include <math.h>  
#include <queue>  
#include <set>  
#include <stdlib.h>  
#include <string.h>  
#include <string>  
#include <time.h>  
#include <unordered_map>  
#include <unordered_set>  
#include <vector>  

#pragma warning(disable:4996)  
#pragma comment(linker, "/STACK:336777216")  
using namespace std;

#define mp make_pair  
#define Fi first  
#define Se second  
#define pb(x) push_back(x)  
#define szz(x) ((int)(x).size())  
#define rep(i, n) for(int i=0;i<n;i++)  
#define all(x) (x).begin(), (x).end()  
#define ldb ldouble  

typedef unsigned int uint;
typedef tuple<int, int, int> t3;
typedef long long ll;
typedef unsigned long long ull;
typedef double db;
typedef long double ldb;
typedef pair <int, int> pii;
typedef pair <ll, ll> pll;
typedef pair <ll, int> pli;
typedef pair <db, db> pdd;

int IT_MAX = 1 << 19;
const ll MOD = 1000000007;
const int INF = 0x3f3f3f3f;
const ll LL_INF = 0x3f3f3f3f3f3f3f3f;
const db PI = acos(-1);
const db ERR = 1e-10;

const int MX = 100005;

int N, M;
int P[MX];

struct UF{
	int t[MX];
	int find(int x){
		return t[x] ? t[x] = find(t[x]) : x;
	}
	int merge(int a, int b){
		a = find(a), b = find(b);
		if(a == b) return false;
		t[a] = b;
		return true;
	}
}uf;

vector<int> Vl[MX];

int main()
{
	scanf("%d%d", &N, &M);
	for(int i = 1; i <= N; i++) scanf("%d", P+i);
	for(int i = 1; i <= M; i++){
		int a, b;
		scanf("%d%d", &a, &b);
		uf.merge(a, b);
	}
	for(int i = 1; i <= N; i++) Vl[uf.find(i)].push_back(i);
	int ans = 0;
	for(int i = 1; i <= N; i++){
		if(uf.find(i) != i) continue;
		set<int> X;
		for(int c : Vl[i]) X.insert(P[c]);
		for(int c : Vl[i]) if(X.find(c) != X.end()) ans++;
	}
	printf("%d\n", ans);
}

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:76:23: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d%d", &N, &M);
                       ^
./Main.cpp:77:46: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
  for(int i = 1; i <= N; i++) scanf("%d", P+i);
                                              ^
./Main.cpp:80:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d%d", &a, &b);
                        ^

Judge Result