oj.uz

Submission #122392

# Submission time Handle Problem Language Result Execution time Memory
122392 2019-06-28T06:55:12 Z 이온조(#2989) Beads and wires (APIO14_beads) C++14
0 / 100
 6 ms 5120 KB 
#include <bits/stdc++.h>
using namespace std;
using pii = pair<int, int>;

vector<pii> adj[200009];
int D[2][200009];

int go(int x, int p, int pc) {
	for(auto& it: adj[x]) if(it.first != p) go(it.first, x, it.second);
	int m1 = -1e9, m2 = -1e9, s = 0;
	for(auto& it: adj[x]) if(it.first != p) s += max(D[0][it.first], D[1][it.first]);
	for(auto& it: adj[x]) if(it.first != p) {
		int n, c; tie(n, c) = it;
		int v = D[0][n] + c - max(D[0][n], D[1][n]);
		if(m1 <= v) m2 = m1, m1 = v;
		else if(m2 <= v) m2 = v;
	}
	D[0][x] = s;
	if(m2 != -1e9) D[0][x] = max(D[0][x], s + m1 + m2);
	if(m1 != -1) D[1][x] = max(D[1][x], s + m1 + pc);
}

int main() {
	int N; scanf("%d",&N);
	for(int i=0; i<N-1; i++) {
		int u, v, w; scanf("%d%d%d",&u,&v,&w);
		adj[u].push_back({v, w});
		adj[v].push_back({u, w});
	}
	int rt;
	for(int i=1; i<=N; i++) if((int)adj[i].size() == 1) rt = i;
	go(rt, rt, -1e9);
	printf("%d", D[0][rt]);
	return 0;
}

Compilation message

beads.cpp: In function 'int go(int, int, int)':
beads.cpp:21:1: warning: no return statement in function returning non-void [-Wreturn-type]
 }
 ^
beads.cpp: In function 'int main()':
beads.cpp:24:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  int N; scanf("%d",&N);
         ~~~~~^~~~~~~~~
beads.cpp:26:21: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   int u, v, w; scanf("%d%d%d",&u,&v,&w);
                ~~~~~^~~~~~~~~~~~~~~~~~~
beads.cpp:33:8: warning: 'rt' may be used uninitialized in this function [-Wmaybe-uninitialized]
  printf("%d", D[0][rt]);
  ~~~~~~^~~~~~~~~~~~~~~~

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 5 ms 4992 KB Output is correct
4 Correct 6 ms 5120 KB Output is correct
5 Correct 6 ms 4992 KB Output is correct
6 Incorrect 5 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 5 ms 4992 KB Output is correct
4 Correct 6 ms 5120 KB Output is correct
5 Correct 6 ms 4992 KB Output is correct
6 Incorrect 5 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 5 ms 4992 KB Output is correct
4 Correct 6 ms 5120 KB Output is correct
5 Correct 6 ms 4992 KB Output is correct
6 Incorrect 5 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 5 ms 4992 KB Output is correct
4 Correct 6 ms 5120 KB Output is correct
5 Correct 6 ms 4992 KB Output is correct
6 Incorrect 5 ms 4992 KB Output isn't correct
7 Halted 0 ms 0 KB -