oj.uz

Submission #19171

# Submission time Handle Problem Language Result Execution time Memory
19171 2016-02-19T10:25:04 Z comet Beads and wires (APIO14_beads) C++14
28 / 100
 1000 ms 14584 KB 
#include <cstdio>
#include <algorithm>
#include <cstring>
#include <vector>
#include <cassert>
#include <unordered_map>
#define pb push_back
using namespace std;
typedef pair<int,int> pp;
struct pt{int u,c;};
typedef vector<int> vec;
typedef vector<pt> vec2;
typedef vector<vec> mat;
typedef vector<vec2> graph;

unordered_map<int,int> ID[200010];

mat dp[2];
graph path;

int N;
int root;

void input(){
	scanf("%d",&N);
	path.assign(N+1,vec2());
	dp[0].assign(N+1,vec());
	dp[1].assign(N+1,vec());

	int x,y,z;
	for(int i=0;i<N-1;i++){
		scanf("%d%d%d",&x,&y,&z);
		ID[x][y]=path[x].size();
		ID[y][x]=path[y].size();
		path[x].pb(pt{y,z});
		path[y].pb(pt{x,z});
		dp[0][x].pb(-1);dp[1][x].pb(-1);
		dp[0][y].pb(-1);dp[1][y].pb(-1);
	}
	for(int i=1;i<=N;i++){
		ID[i][i]=path[i].size();
		dp[0][i].pb(-1);
		dp[1][i].pb(-1);
	}
}

void process(int v,int p,int mode){
	int sz=path[v].size();
	int cnt=sz-(v!=root);
	int& ret=dp[mode][v][ID[v][p]];
	ret=0;
	if(cnt==0){
		if(mode==1)ret = -1e9;
		return;
	}

	vec a;
	for(int i=0;i<sz;i++){
		int u=path[v][i].u;
		int c=path[v][i].c;
		int id=ID[u][v];
		if(p==u)continue;
		int z = max(dp[0][u][id],dp[1][u][id]+c);
		ret+=z;
		if(mode==1){
			a.pb(dp[0][u][id]+c-z);
		}
	}
	
	if(mode==1){ // mode==1
		ret+=*max_element(a.begin(),a.end());
	}
}

void dfs(int v,int p,int mode){

	int& ret=dp[mode][v][ID[v][p]];
	if(~ret)return;
	
	for(int i=0;i<path[v].size();i++){
		int u=path[v][i].u;
		if(u==p)continue;
		dfs(u,v,0);
		dfs(u,v,1);
	}
	process(v,p,mode);
}

void PS(){

	int ans=0;
	for(int i=1;i<=N;i++){
		root=i;
		dfs(i,i,0);
		ans=max(ans,dp[0][i][ID[i][i]]);
	}
	printf("%d\n",ans);

}

int main(){
	input();
	PS();
	return 0;
}

Compilation message

beads.cpp: In function 'void dfs(int, int, int)':
beads.cpp:80:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i=0;i<path[v].size();i++){
              ~^~~~~~~~~~~~~~~
beads.cpp: In function 'void input()':
beads.cpp:25:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d",&N);
  ~~~~~^~~~~~~~~
beads.cpp:32:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d%d%d",&x,&y,&z);
   ~~~~~^~~~~~~~~~~~~~~~~~~

Subtask #1
13.0 / 13.0

# Verdict Execution time Memory Grader output
1 Correct 11 ms 11264 KB Output is correct
2 Correct 11 ms 11264 KB Output is correct
3 Correct 11 ms 11264 KB Output is correct
4 Correct 11 ms 11264 KB Output is correct
5 Correct 12 ms 11264 KB Output is correct
6 Correct 10 ms 11264 KB Output is correct
7 Correct 11 ms 11264 KB Output is correct
8 Correct 11 ms 11236 KB Output is correct
9 Correct 11 ms 11264 KB Output is correct
10 Correct 11 ms 11264 KB Output is correct
11 Correct 11 ms 11264 KB Output is correct
12 Correct 11 ms 11264 KB Output is correct

Subtask #2
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 11 ms 11264 KB Output is correct
2 Correct 11 ms 11264 KB Output is correct
3 Correct 11 ms 11264 KB Output is correct
4 Correct 11 ms 11264 KB Output is correct
5 Correct 12 ms 11264 KB Output is correct
6 Correct 10 ms 11264 KB Output is correct
7 Correct 11 ms 11264 KB Output is correct
8 Correct 11 ms 11236 KB Output is correct
9 Correct 11 ms 11264 KB Output is correct
10 Correct 11 ms 11264 KB Output is correct
11 Correct 11 ms 11264 KB Output is correct
12 Correct 11 ms 11264 KB Output is correct
13 Correct 12 ms 11264 KB Output is correct
14 Correct 13 ms 11264 KB Output is correct
15 Correct 12 ms 11328 KB Output is correct
16 Correct 13 ms 11392 KB Output is correct
17 Correct 13 ms 11392 KB Output is correct
18 Correct 13 ms 11392 KB Output is correct
19 Correct 17 ms 11392 KB Output is correct
20 Correct 14 ms 11264 KB Output is correct
21 Correct 16 ms 11392 KB Output is correct
22 Correct 13 ms 11392 KB Output is correct

Subtask #3
0 / 29.0

# Verdict Execution time Memory Grader output
1 Correct 11 ms 11264 KB Output is correct
2 Correct 11 ms 11264 KB Output is correct
3 Correct 11 ms 11264 KB Output is correct
4 Correct 11 ms 11264 KB Output is correct
5 Correct 12 ms 11264 KB Output is correct
6 Correct 10 ms 11264 KB Output is correct
7 Correct 11 ms 11264 KB Output is correct
8 Correct 11 ms 11236 KB Output is correct
9 Correct 11 ms 11264 KB Output is correct
10 Correct 11 ms 11264 KB Output is correct
11 Correct 11 ms 11264 KB Output is correct
12 Correct 11 ms 11264 KB Output is correct
13 Correct 12 ms 11264 KB Output is correct
14 Correct 13 ms 11264 KB Output is correct
15 Correct 12 ms 11328 KB Output is correct
16 Correct 13 ms 11392 KB Output is correct
17 Correct 13 ms 11392 KB Output is correct
18 Correct 13 ms 11392 KB Output is correct
19 Correct 17 ms 11392 KB Output is correct
20 Correct 14 ms 11264 KB Output is correct
21 Correct 16 ms 11392 KB Output is correct
22 Correct 13 ms 11392 KB Output is correct
23 Correct 28 ms 12800 KB Output is correct
24 Correct 29 ms 12800 KB Output is correct
25 Correct 31 ms 12888 KB Output is correct
26 Correct 46 ms 14464 KB Output is correct
27 Correct 54 ms 14456 KB Output is correct
28 Execution timed out 1086 ms 14584 KB Time limit exceeded
29 Halted 0 ms 0 KB -

Subtask #4
0 / 43.0

# Verdict Execution time Memory Grader output
1 Correct 11 ms 11264 KB Output is correct
2 Correct 11 ms 11264 KB Output is correct
3 Correct 11 ms 11264 KB Output is correct
4 Correct 11 ms 11264 KB Output is correct
5 Correct 12 ms 11264 KB Output is correct
6 Correct 10 ms 11264 KB Output is correct
7 Correct 11 ms 11264 KB Output is correct
8 Correct 11 ms 11236 KB Output is correct
9 Correct 11 ms 11264 KB Output is correct
10 Correct 11 ms 11264 KB Output is correct
11 Correct 11 ms 11264 KB Output is correct
12 Correct 11 ms 11264 KB Output is correct
13 Correct 12 ms 11264 KB Output is correct
14 Correct 13 ms 11264 KB Output is correct
15 Correct 12 ms 11328 KB Output is correct
16 Correct 13 ms 11392 KB Output is correct
17 Correct 13 ms 11392 KB Output is correct
18 Correct 13 ms 11392 KB Output is correct
19 Correct 17 ms 11392 KB Output is correct
20 Correct 14 ms 11264 KB Output is correct
21 Correct 16 ms 11392 KB Output is correct
22 Correct 13 ms 11392 KB Output is correct
23 Correct 28 ms 12800 KB Output is correct
24 Correct 29 ms 12800 KB Output is correct
25 Correct 31 ms 12888 KB Output is correct
26 Correct 46 ms 14464 KB Output is correct
27 Correct 54 ms 14456 KB Output is correct
28 Execution timed out 1086 ms 14584 KB Time limit exceeded
29 Halted 0 ms 0 KB -