oj.uz

Submission #69792

# Submission time Handle Problem Language Result Execution time Memory
69792 2018-08-21T13:41:32 Z E869120 Friend (IOI14_friend) C++14
69 / 100
 52 ms 5544 KB 
#include "friend.h"
#include <algorithm>
#include <vector>
#include <iostream>
#include <cassert>
using namespace std;

// Find out best sample

struct edge {
	int to, cap, rev;
};

class MaximumFlow {
public:
	vector<vector<edge>>X; vector<bool>used; int size_ = 0;

	void init(int sz) {
		size_ = sz;
		X.resize(size_, vector<edge>(0, edge{ 0,0,0 }));
		used.resize(size_, false);
	}
	void add_edge(int a, int b, int c) {
		X[a].push_back(edge{ b,c,(int)X[b].size() });
		X[b].push_back(edge{ a,0,(int)X[a].size() - 1 });
	}
	int dfs(int pos, int to, int f) {
		if (pos == to) return f;
		used[pos] = true;

		for (int i = 0; i < X[pos].size(); i++) {
			if (used[X[pos][i].to] == true || X[pos][i].cap == 0) continue;
			int S = dfs(X[pos][i].to, to, min(f, X[pos][i].cap));
			if (S > 0) {
				X[pos][i].cap -= S;
				X[X[pos][i].to][X[pos][i].rev].cap += S;
				return S;
			}
		}
		return 0;
	}
	int max_flow(int u, int v) {
		int Flow = 0;
		while (true) {
			for (int i = 0; i < size_; i++) used[i] = false;
			int E = dfs(u, v, 1000000007);
			Flow += E; if (E == 0) break;
		}
		return Flow;
	}
};

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

void init() {
	for (int i = 0; i < 15; i++) { for (int j = 0; j < 15; j++) p[i][j] = 0; dp[i][0] = 0; dp[i][1] = 0; conf[i] = 0; x[i].clear(); col[i] = 0; }
}

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];
}

void dfs2(int pos, int dep) {
	if (col[pos] >= 0) return;
	col[pos] = dep;
	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; init();
	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 <= 10) {
		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;
			for (int i = 0; i < n; i++) { if (col[i] == -1) dfs2(i, 0); }
			MaximumFlow L; L.init(n + 2);
			for (int i = 0; i < n; i++) {
				for (int j = 0; j < n; j++) {
					if (p[i][j] == 1 && col[i] == 0 && col[j] == 1) L.add_edge(i, j, 1);
				}
			}
			for (int i = 0; i < n; i++) {
				if (col[i] == 0) L.add_edge(n, i, 1);
				if (col[i] == 1) L.add_edge(i, n + 1, 1);
			}
			int Z = L.max_flow(n, n + 1);
			return n - Z;
		}
	}
	return -1;
}

Compilation message

friend.cpp: In member function 'int MaximumFlow::dfs(int, int, int)':
friend.cpp:31:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for (int i = 0; i < X[pos].size(); i++) {
                   ~~^~~~~~~~~~~~~~~
friend.cpp: In function 'void dfs(int)':
friend.cpp:61:20: 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:63:20: 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:64:20: 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 'int findSample(int, int*, int*, int*)':
friend.cpp:97:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
    for (int j = 0; j < vec.size(); j++) {
                    ~~^~~~~~~~~~~~
friend.cpp:98:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (int k = j + 1; k < vec.size(); k++) {
                         ~~^~~~~~~~~~~~
friend.cpp:103:35: 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]];
                                 ~~^~~~~~~~~~~~

Subtask #1
11.0 / 11.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 376 KB Output is correct
2 Correct 3 ms 492 KB Output is correct
3 Correct 2 ms 572 KB Output is correct
4 Correct 3 ms 724 KB Output is correct
5 Correct 3 ms 724 KB Output is correct
6 Correct 3 ms 724 KB Output is correct
7 Correct 3 ms 724 KB Output is correct
8 Correct 2 ms 724 KB Output is correct
9 Correct 3 ms 724 KB Output is correct
10 Correct 2 ms 724 KB Output is correct
11 Correct 3 ms 724 KB Output is correct
12 Correct 3 ms 724 KB Output is correct
13 Correct 3 ms 772 KB Output is correct
14 Correct 2 ms 772 KB Output is correct
15 Correct 3 ms 772 KB Output is correct
16 Correct 3 ms 772 KB Output is correct
17 Correct 3 ms 772 KB Output is correct

Subtask #2
8.0 / 8.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 772 KB Output is correct
2 Correct 3 ms 772 KB Output is correct
3 Correct 4 ms 772 KB Output is correct
4 Correct 7 ms 824 KB Output is correct
5 Correct 7 ms 836 KB Output is correct
6 Correct 4 ms 836 KB Output is correct
7 Correct 3 ms 856 KB Output is correct
8 Correct 5 ms 872 KB Output is correct
9 Correct 5 ms 872 KB Output is correct
10 Correct 6 ms 880 KB Output is correct

Subtask #3
8.0 / 8.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 2440 KB Output is correct
2 Correct 12 ms 4492 KB Output is correct
3 Correct 3 ms 4492 KB Output is correct
4 Correct 9 ms 4492 KB Output is correct
5 Correct 13 ms 4520 KB Output is correct
6 Correct 3 ms 4520 KB Output is correct
7 Correct 4 ms 4520 KB Output is correct
8 Correct 4 ms 4520 KB Output is correct
9 Correct 4 ms 4520 KB Output is correct
10 Correct 15 ms 4808 KB Output is correct

Subtask #4
19.0 / 19.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 4808 KB Output is correct
2 Correct 2 ms 4808 KB Output is correct
3 Correct 2 ms 4808 KB Output is correct
4 Correct 2 ms 4808 KB Output is correct
5 Correct 6 ms 4856 KB Output is correct
6 Correct 6 ms 4856 KB Output is correct
7 Correct 4 ms 4856 KB Output is correct
8 Correct 6 ms 4856 KB Output is correct
9 Correct 3 ms 4856 KB Output is correct
10 Correct 4 ms 4856 KB Output is correct
11 Correct 4 ms 4856 KB Output is correct
12 Correct 7 ms 4856 KB Output is correct
13 Correct 5 ms 4856 KB Output is correct
14 Correct 3 ms 4856 KB Output is correct
15 Correct 6 ms 4856 KB Output is correct

Subtask #5
23.0 / 23.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 4856 KB Output is correct
2 Correct 2 ms 4856 KB Output is correct
3 Correct 3 ms 4856 KB Output is correct
4 Correct 3 ms 4856 KB Output is correct
5 Correct 3 ms 4856 KB Output is correct
6 Correct 3 ms 4856 KB Output is correct
7 Correct 3 ms 4856 KB Output is correct
8 Correct 2 ms 4856 KB Output is correct
9 Correct 7 ms 4984 KB Output is correct
10 Correct 5 ms 4984 KB Output is correct
11 Correct 5 ms 4984 KB Output is correct
12 Correct 6 ms 4984 KB Output is correct
13 Correct 5 ms 4984 KB Output is correct
14 Correct 11 ms 4984 KB Output is correct
15 Correct 6 ms 4984 KB Output is correct
16 Correct 5 ms 4984 KB Output is correct
17 Correct 3 ms 4984 KB Output is correct
18 Correct 4 ms 4984 KB Output is correct
19 Correct 4 ms 4984 KB Output is correct
20 Correct 8 ms 4984 KB Output is correct
21 Correct 11 ms 5056 KB Output is correct

Subtask #6
0 / 31.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 5056 KB Output is correct
2 Correct 2 ms 5056 KB Output is correct
3 Correct 3 ms 5056 KB Output is correct
4 Correct 3 ms 5056 KB Output is correct
5 Correct 4 ms 5056 KB Output is correct
6 Correct 3 ms 5056 KB Output is correct
7 Correct 2 ms 5056 KB Output is correct
8 Correct 3 ms 5056 KB Output is correct
9 Correct 3 ms 5056 KB Output is correct
10 Correct 2 ms 5056 KB Output is correct
11 Correct 4 ms 5056 KB Output is correct
12 Runtime error 52 ms 5544 KB Execution killed with signal 11 (could be triggered by violating memory limits)
13 Halted 0 ms 0 KB -