oj.uz

Submission #19175

# Submission time Handle Problem Language Result Execution time Memory
19175 2016-02-19T11:52:30 Z comet Beads and wires (APIO14_beads) C++14
57 / 100
 1000 ms 79736 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;
bool chk[200010];
int sum[200010];
int Max[200010][2];
int Maxi[200010][2];
int par[200010];

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);
	}
}

int getMax(int v,vec2& a){
	int Max1=-1e9,Max2=-1e9;
	int id1=0,id2=0;
	for(int i=0;i<a.size();i++){
		if(a[i].c>=Max1){
			Max2=Max1;
			id2=id1;
			Max1=a[i].c;
			id1=a[i].u;
		}else if(a[i].c>Max2){
			Max2=a[i].c;
			id2=a[i].u;
		}
	}
	Max[v][0]=Max1;Maxi[v][0]=id1;
	Max[v][1]=Max2;Maxi[v][1]=id2;
	return Max1;
}

void process(int v,int p){
	int sz=path[v].size();
	int cnt=sz-(v!=root);
	int& ret0=dp[0][v][ID[v][p]];
	int& ret1=dp[1][v][ID[v][p]];
	if(cnt==0){
		ret0=0;
		ret1=-1e9;
		return;
	}

	vec2 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);
		sum[v]+=z;
		a.pb(pt{u,dp[0][u][id]+c-z});
	}

	ret0=ret1=sum[v];
	ret1+=getMax(v,a);
}

void dfs(int v,int p){

	int& ret=dp[0][v][ID[v][p]];
	if(~ret)return;
	
	par[v]=p;
	for(int i=0;i<path[v].size();i++){
		int u=path[v][i].u;
		if(u==p)continue;
		dfs(u,v);
	}
	
	process(v,p);
//	printf("%d %d %d : %d\n",v,p,mode,dp[mode][v][ID[v][p]]);
}

void process2(int v,int p){
	int sz=path[v].size();
	int cnt=sz-1;
	int& ret0=dp[0][v][ID[v][p]];
	int& ret1=dp[1][v][ID[v][p]];

	if(cnt==0){
		ret0 = 0;
		ret1 = -1e9;
		return;
	}
	if(v==p)return;

	int id=ID[p][v];
	int c=path[p][id].c;
	int z=0;
	ret0 = ret1 = sum[v] - max(dp[0][p][id],dp[1][p][id]+c);

	if(v!=root){
		id = ID[par[v]][v];
		c = path[par[v]][id].c;
		z = max(dp[0][par[v]][id],dp[1][par[v]][id]+c);
		ret0 += z;
		ret1 += z;
		if(Maxi[v][0]!=p){
			ret1+=max(Max[v][0],dp[0][par[v]][id]+c-z);
		}else{
			ret1+=max(Max[v][1],dp[0][par[v]][id]+c-z);
		}
	}else{
		if(Maxi[v][0]!=p){
			ret1+=Max[v][0];
		}else{
			ret1+=Max[v][1];
		}
	}
}

void dfs2(int v,int p){

	int& ret=dp[0][v][ID[v][p]];
	if(~ret)return;
	
	if(v==root){
		process2(v,p);
		return;
	}

	dfs2(par[v],v);
	if(v!=p)process2(v,p);

//	printf("%d %d %d : %d\n",v,p,mode,dp[mode][v][ID[v][p]]);

}

int process3(int v){
	int ret=0;
	int sz=path[v].size();
	for(int i=0;i<sz;i++){
		int u=path[v][i].u;
		int c=path[v][i].c;
		int id=ID[u][v];
		int z = max(dp[0][u][id],dp[1][u][id]+c);
		ret+=z;
	}
	return ret;
}

void PS(){

	for(int i=1;i<=N;i++){
		for(int j=0;j<2;j++){
			Max[i][j]=-1e9;
		}
	}

	root=1;
	int ans=0;

	dfs(1,1);

	for(int i=2;i<=N;i++){
		if(path[i].size()==1)dfs2(i,i);
	}

	for(int i=1;i<=N;i++){
		ans=max(ans,process3(i));
	}
	printf("%d\n",ans);

}

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

Compilation message

beads.cpp: In function 'int getMax(int, vec2&)':
beads.cpp:55:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i=0;i<a.size();i++){
              ~^~~~~~~~~
beads.cpp: In function 'void dfs(int, int)':
beads.cpp:103:15: 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:30:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d",&N);
  ~~~~~^~~~~~~~~
beads.cpp:37:8: 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 12 ms 11264 KB Output is correct
2 Correct 12 ms 11264 KB Output is correct
3 Correct 11 ms 11236 KB Output is correct
4 Correct 12 ms 11264 KB Output is correct
5 Correct 11 ms 11264 KB Output is correct
6 Correct 11 ms 11264 KB Output is correct
7 Correct 13 ms 11264 KB Output is correct
8 Correct 12 ms 11236 KB Output is correct
9 Correct 12 ms 11264 KB Output is correct
10 Correct 12 ms 11264 KB Output is correct
11 Correct 11 ms 11264 KB Output is correct
12 Correct 12 ms 11264 KB Output is correct

Subtask #2
15.0 / 15.0

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

Subtask #3
29.0 / 29.0

# Verdict Execution time Memory Grader output
1 Correct 12 ms 11264 KB Output is correct
2 Correct 12 ms 11264 KB Output is correct
3 Correct 11 ms 11236 KB Output is correct
4 Correct 12 ms 11264 KB Output is correct
5 Correct 11 ms 11264 KB Output is correct
6 Correct 11 ms 11264 KB Output is correct
7 Correct 13 ms 11264 KB Output is correct
8 Correct 12 ms 11236 KB Output is correct
9 Correct 12 ms 11264 KB Output is correct
10 Correct 12 ms 11264 KB Output is correct
11 Correct 11 ms 11264 KB Output is correct
12 Correct 12 ms 11264 KB Output is correct
13 Correct 12 ms 11264 KB Output is correct
14 Correct 12 ms 11392 KB Output is correct
15 Correct 12 ms 11392 KB Output is correct
16 Correct 12 ms 11392 KB Output is correct
17 Correct 13 ms 11392 KB Output is correct
18 Correct 12 ms 11392 KB Output is correct
19 Correct 12 ms 11392 KB Output is correct
20 Correct 12 ms 11392 KB Output is correct
21 Correct 12 ms 11392 KB Output is correct
22 Correct 12 ms 11392 KB Output is correct
23 Correct 23 ms 13056 KB Output is correct
24 Correct 24 ms 13028 KB Output is correct
25 Correct 24 ms 13056 KB Output is correct
26 Correct 39 ms 14712 KB Output is correct
27 Correct 46 ms 14720 KB Output is correct
28 Correct 35 ms 14844 KB Output is correct
29 Correct 44 ms 14840 KB Output is correct
30 Correct 37 ms 14848 KB Output is correct
31 Correct 42 ms 14976 KB Output is correct

Subtask #4
0 / 43.0

# Verdict Execution time Memory Grader output
1 Correct 12 ms 11264 KB Output is correct
2 Correct 12 ms 11264 KB Output is correct
3 Correct 11 ms 11236 KB Output is correct
4 Correct 12 ms 11264 KB Output is correct
5 Correct 11 ms 11264 KB Output is correct
6 Correct 11 ms 11264 KB Output is correct
7 Correct 13 ms 11264 KB Output is correct
8 Correct 12 ms 11236 KB Output is correct
9 Correct 12 ms 11264 KB Output is correct
10 Correct 12 ms 11264 KB Output is correct
11 Correct 11 ms 11264 KB Output is correct
12 Correct 12 ms 11264 KB Output is correct
13 Correct 12 ms 11264 KB Output is correct
14 Correct 12 ms 11392 KB Output is correct
15 Correct 12 ms 11392 KB Output is correct
16 Correct 12 ms 11392 KB Output is correct
17 Correct 13 ms 11392 KB Output is correct
18 Correct 12 ms 11392 KB Output is correct
19 Correct 12 ms 11392 KB Output is correct
20 Correct 12 ms 11392 KB Output is correct
21 Correct 12 ms 11392 KB Output is correct
22 Correct 12 ms 11392 KB Output is correct
23 Correct 23 ms 13056 KB Output is correct
24 Correct 24 ms 13028 KB Output is correct
25 Correct 24 ms 13056 KB Output is correct
26 Correct 39 ms 14712 KB Output is correct
27 Correct 46 ms 14720 KB Output is correct
28 Correct 35 ms 14844 KB Output is correct
29 Correct 44 ms 14840 KB Output is correct
30 Correct 37 ms 14848 KB Output is correct
31 Correct 42 ms 14976 KB Output is correct
32 Correct 303 ms 28444 KB Output is correct
33 Correct 309 ms 28424 KB Output is correct
34 Correct 520 ms 28408 KB Output is correct
35 Execution timed out 1080 ms 79736 KB Time limit exceeded
36 Halted 0 ms 0 KB -