oj.uz

Submission #96167

# Submission time Handle Problem Language Result Execution time Memory
96167 2019-02-06T15:46:05 Z Retro3014 Beads and wires (APIO14_beads) C++17
0 / 100
 6 ms 5120 KB 
#include <iostream>
#include <vector>
#include <algorithm>
#include <stdio.h>

#define MAX_N 200000
#define INF 2000000000
using namespace std;

int N;
int ans;
struct S{
	S (int idx, int data) : idx(idx), data(data) {}
	int idx, data;
};
vector<S> gp[MAX_N+1];
vector<S> p;
int dp[MAX_N+1][2];

void dfs(int x){
	for(int i=0; i<gp[x].size(); i++){
		if(gp[x][i].idx!=p[x].idx){
			p[gp[x][i].idx].idx = x;
			p[gp[x][i].idx].data = gp[x][i].data;
			dfs(gp[x][i].idx);
		}
	}
	int mx = 0;
	for(int i=0; i<gp[x].size(); i++){
		if(gp[x][i].idx==p[x].idx)	continue;
		mx += max(dp[gp[x][i].idx][0], dp[gp[x][i].idx][1]);
	}
	dp[x][0] = mx;
	dp[x][1] = -INF;
	int sum = mx;
	bool tf = false;
	mx = 0;
	for(int i=0; i<gp[x].size(); i++){
		if(gp[x][i].idx==p[x].idx)	continue;
		if(!tf){
			tf = true;
			mx = dp[gp[x][i].idx][0]-max(dp[gp[x][i].idx][0], dp[gp[x][i].idx][1])+gp[x][i].data;
		}else{
			dp[x][0] = max(dp[x][0], sum+mx+(dp[gp[x][i].idx][0]-max(dp[gp[x][i].idx][0], dp[gp[x][i].idx][1])+gp[x][i].data));
			mx = max(mx, dp[gp[x][i].idx][0]-max(dp[gp[x][i].idx][0], dp[gp[x][i].idx][1])+gp[x][i].data);
		}
		dp[x][1] = max(dp[x][1], sum + p[x].data + (dp[gp[x][i].idx][0]-max(dp[gp[x][i].idx][0], dp[gp[x][i].idx][1])+gp[x][i].data));
	}
	return;
}


int main(){
	scanf("%d", &N);
	for(int i=0; i<=N; i++)	p.push_back({0, 0});
	for(int i=0; i<N-1; i++){
		int a, b, c;
		scanf("%d%d%d", &a, &b, &c);
		gp[a].push_back({b, c}); gp[b].push_back({a, c});
	}
	dfs(1);
	printf("%d", dp[1][0]);
	return 0;
}

Compilation message

beads.cpp: In function 'void dfs(int)':
beads.cpp:21:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i=0; i<gp[x].size(); i++){
               ~^~~~~~~~~~~~~
beads.cpp:29:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i=0; i<gp[x].size(); i++){
               ~^~~~~~~~~~~~~
beads.cpp:38:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i=0; i<gp[x].size(); i++){
               ~^~~~~~~~~~~~~
beads.cpp: In function 'int main()':
beads.cpp:54:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d", &N);
  ~~~~~^~~~~~~~~~
beads.cpp:58:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d%d%d", &a, &b, &c);
   ~~~~~^~~~~~~~~~~~~~~~~~~~~~

Subtask #1
0 / 13.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 4992 KB Output is correct
2 Correct 6 ms 4992 KB Output is correct
3 Correct 6 ms 5120 KB Output is correct
4 Correct 6 ms 4992 KB Output is correct
5 Correct 6 ms 4992 KB Output is correct
6 Incorrect 6 ms 4992 KB Output isn't correct
7 Halted 0 ms 0 KB -

Subtask #2
0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 4992 KB Output is correct
2 Correct 6 ms 4992 KB Output is correct
3 Correct 6 ms 5120 KB Output is correct
4 Correct 6 ms 4992 KB Output is correct
5 Correct 6 ms 4992 KB Output is correct
6 Incorrect 6 ms 4992 KB Output isn't correct
7 Halted 0 ms 0 KB -

Subtask #3
0 / 29.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 4992 KB Output is correct
2 Correct 6 ms 4992 KB Output is correct
3 Correct 6 ms 5120 KB Output is correct
4 Correct 6 ms 4992 KB Output is correct
5 Correct 6 ms 4992 KB Output is correct
6 Incorrect 6 ms 4992 KB Output isn't correct
7 Halted 0 ms 0 KB -

Subtask #4
0 / 43.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 4992 KB Output is correct
2 Correct 6 ms 4992 KB Output is correct
3 Correct 6 ms 5120 KB Output is correct
4 Correct 6 ms 4992 KB Output is correct
5 Correct 6 ms 4992 KB Output is correct
6 Incorrect 6 ms 4992 KB Output isn't correct
7 Halted 0 ms 0 KB -