Submission #3879048

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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;

set<int> T[MX];
int chk[MX];
char C[MX];

pii dfs(int x, int p){
	pii r = pii(0, 0);
	int cur = (T[x].size()%2 == 0) != (C[x] == 'B');
	for(int c : T[x]){
		if(c == p) continue;
		pii t = dfs(c, x);	
		r.first = max({r.first, t.first, r.second + t.second + cur});
		r.second = max(r.second, t.second);
	}
	r.second += cur;
	return r;
}

int main()
{
	int N;
	scanf("%d", &N);
	for(int i = 1; i < N; i++){
		int a, b;
		scanf("%d%d", &a, &b);
		T[a].insert(b);
		T[b].insert(a);
	}
	scanf("%s", C+1);
	queue<int> Q;
	for(int i = 1; i <= N; i++) if(T[i].size() == 1) Q.push(i);
	while(Q.size()){
		int p = Q.front(); Q.pop();
		if(C[p] == 'W') continue;
		chk[p] = 1;
		int n = *T[p].begin();
		T[p].clear();
		T[n].erase(p);
		if(T[n].size() == 1) Q.push(n);
	}
	int r = 0;
	for(int i = 1; i <= N; i++) if(!chk[i]) r = i;
	if(r == 0) return !printf("0\n");

	int ans = -2;
	for(int i = 1; i <= N; i++){
		if(!chk[i]) ans += 2;
		if((T[i].size()%2 == 0) != (C[i] == 'B')) ans++;
	}
	pii t = dfs(r, -1);
	ans -= t.first * 2;
	printf("%d\n", ans);
}

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:76:17: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d", &N);
                 ^
./Main.cpp:79:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d%d", &a, &b);
                        ^
./Main.cpp:83:18: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
  scanf("%s", C+1);
                  ^

Judge Result