제출 #69768

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
69768		E869120	Friend (IOI14_friend)	C++14	35 / 100	13 ms	4604 KiB

friend

#include "friend.h"
#include <algorithm>
#include <vector>
#include <iostream>
#include <cassert>
using namespace std;

// Find out best sample

int p[1009][1009], N; vector<int>x[1009];
int dp[1009][2], conf[1009], col[1009];

void dfs(int pos) {
	for (int i = 0; i < x[pos].size(); i++) dfs(x[pos][i]);

	for (int i = 0; i < x[pos].size(); i++) dp[pos][0] += max(dp[x[pos][i]][0], dp[x[pos][i]][1]);
	for (int i = 0; i < x[pos].size(); i++) dp[pos][1] += dp[x[pos][i]][0];
	dp[pos][1] += conf[pos];
}

int G1 = 0, G2 = 0;

void dfs2(int pos, int dep) {
	if (col[pos] >= 0) {
		assert(col[pos] == dep);
		return;
	}
	col[pos] = dep;
	if (dep == 0) G1++; if (dep == 1) G2++;

	for (int i = 0; i < N; i++) {
		if (p[pos][i] == 1) dfs2(i, dep ^ 1);
	}
}

int findSample(int n, int confidence[], int host[], int protocol[]) {
	N = n;
	if (n <= 1000) {
		for (int i = 1; i <= n - 1; i++) {
			if (protocol[i] == 0 || protocol[i] == 2) {
				p[host[i]][i] = 1;
				p[i][host[i]] = 1;
			}
			if (protocol[i] == 1 || protocol[i] == 2) {
				for (int j = 0; j < n; j++) {
					if (p[host[i]][j] == 1) {
						p[j][i] = 1; p[i][j] = 1;
					}
				}
			}
		}
	}
	if (n <= 2) {
		int maxn = 0;
		for (int i = 0; i < (1 << n); i++) {
			vector<int>vec;
			for (int j = 0; j < n; j++) { if ((i / (1 << j)) % 2 == 1) vec.push_back(j); }
			bool OK = true;
			for (int j = 0; j < vec.size(); j++) {
				for (int k = j + 1; k < vec.size(); k++) {
					if (p[vec[j]][vec[k]] == 1) OK = false;
				}
			}
			if (OK == false) continue;
			int bit = 0; for (int j = 0; j < vec.size(); j++) bit += confidence[vec[j]];
			maxn = max(maxn, bit);
		}
		return maxn;
	}
	else {
		int c[3] = { 0,0,0 }; for (int i = 1; i < n; i++) c[protocol[i]] = 1;
		int bit = c[0] * 1 + c[1] * 2 + c[2] * 4;
		for (int i = 0; i < n; i++) conf[i] = confidence[i];

		if (bit == 4) {
			int maxn = 0;
			for (int i = 0; i < n; i++) maxn = max(maxn, confidence[i]);
			return maxn;
		}
		if (bit == 2) {
			int cnts = 0;
			for (int i = 0; i < n; i++) cnts += confidence[i];
			return cnts;
		}
		if (bit == 1) {
			for (int i = 1; i < n; i++) { x[host[i]].push_back(i); }
			dfs(0);
			return max(dp[0][0], dp[0][1]);
		}
		if (bit == 3) {
			for (int i = 0; i < n; i++) col[i] = -1;
			int ret = 0;
			for (int i = 0; i < n; i++) {
				if (col[i] >= 0) continue;
				G1 = 0; G2 = 0;
				dfs2(i, 0);
				ret += max(G1, G2);
			}
			return ret;
		}
	}
	return -1;
}

컴파일 시 표준 에러 (stderr) 메시지

friend.cpp: In function 'void dfs(int)':
friend.cpp:14:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (int i = 0; i < x[pos].size(); i++) dfs(x[pos][i]);
                  ~~^~~~~~~~~~~~~~~
friend.cpp:16:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (int i = 0; i < x[pos].size(); i++) dp[pos][0] += max(dp[x[pos][i]][0], dp[x[pos][i]][1]);
                  ~~^~~~~~~~~~~~~~~
friend.cpp:17:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (int i = 0; i < x[pos].size(); i++) dp[pos][1] += dp[x[pos][i]][0];
                  ~~^~~~~~~~~~~~~~~
friend.cpp: In function 'void dfs2(int, int)':
friend.cpp:29:2: warning: this 'if' clause does not guard... [-Wmisleading-indentation]
  if (dep == 0) G1++; if (dep == 1) G2++;
  ^~
friend.cpp:29:22: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'if'
  if (dep == 0) G1++; if (dep == 1) G2++;
                      ^~
friend.cpp: In function 'int findSample(int, int*, int*, int*)':
friend.cpp:59:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
    for (int j = 0; j < vec.size(); j++) {
                    ~~^~~~~~~~~~~~
friend.cpp:60:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (int k = j + 1; k < vec.size(); k++) {
                         ~~^~~~~~~~~~~~
friend.cpp:65:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
    int bit = 0; for (int j = 0; j < vec.size(); j++) bit += confidence[vec[j]];
                                 ~~^~~~~~~~~~~~

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