oj.uz

Submission #19172

# Submission time Handle Problem Language Result Execution time Memory
19172 2016-02-19T11:43:02 Z comet Beads and wires (APIO14_beads) C++14
57 / 100
 1000 ms 79716 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 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;
	}

	vec2 a;
	sum[v]=0;
	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;
		if(mode==1){
			a.pb(pt{u,dp[0][u][id]+c-z});
		}
	}

	ret=sum[v];
	if(mode==1){
		ret+=getMax(v,a);
	}
}

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

	int& ret=dp[mode][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,0);
		dfs(u,v,1);
	}
	
	process(v,p,mode);
//	printf("%d %d %d : %d\n",v,p,mode,dp[mode][v][ID[v][p]]);
}

void process2(int v,int p,int mode){
	int sz=path[v].size();
	int cnt=sz-1;
	int& ret=dp[mode][v][ID[v][p]];
	ret=0;
	if(cnt==0){
		if(mode==1)ret = -1e9;
		return;
	}
	if(v==p)return;

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

void dfs2(int v,int p,int mode){

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

	dfs2(par[v],v,0);
	dfs2(par[v],v,1);
	if(v!=p)process2(v,p,mode);

//	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(1,1,0);
	dfs(1,1,1);
	
	/*
	printf("%d\n",dp[0][1][ID[1][1]]);
	for(int i=1;i<=N;i++){
		printf("%d : %d / ",i,sum[i]);
		for(int j=0;j<2;j++){
			printf("%d(%d) ",Max[i][j],Maxi[i][j]);
		}
		puts("");
	}
*/

	for(int i=2;i<=N;i++){
		if(path[i].size()==1)dfs2(i,i,0);
	}

	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, int)':
beads.cpp:107:15: 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 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 11 ms 11264 KB Output is correct
6 Correct 11 ms 11264 KB Output is correct
7 Correct 12 ms 11264 KB Output is correct
8 Correct 11 ms 11272 KB Output is correct
9 Correct 12 ms 11264 KB Output is correct
10 Correct 11 ms 11264 KB Output is correct
11 Correct 12 ms 11264 KB Output is correct
12 Correct 11 ms 11344 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 11 ms 11264 KB Output is correct
6 Correct 11 ms 11264 KB Output is correct
7 Correct 12 ms 11264 KB Output is correct
8 Correct 11 ms 11272 KB Output is correct
9 Correct 12 ms 11264 KB Output is correct
10 Correct 11 ms 11264 KB Output is correct
11 Correct 12 ms 11264 KB Output is correct
12 Correct 11 ms 11344 KB Output is correct
13 Correct 12 ms 11308 KB Output is correct
14 Correct 11 ms 11392 KB Output is correct
15 Correct 11 ms 11392 KB Output is correct
16 Correct 11 ms 11392 KB Output is correct
17 Correct 13 ms 11520 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 11 ms 11392 KB Output is correct
22 Correct 11 ms 11392 KB Output is correct

Subtask #3
29.0 / 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 11 ms 11264 KB Output is correct
6 Correct 11 ms 11264 KB Output is correct
7 Correct 12 ms 11264 KB Output is correct
8 Correct 11 ms 11272 KB Output is correct
9 Correct 12 ms 11264 KB Output is correct
10 Correct 11 ms 11264 KB Output is correct
11 Correct 12 ms 11264 KB Output is correct
12 Correct 11 ms 11344 KB Output is correct
13 Correct 12 ms 11308 KB Output is correct
14 Correct 11 ms 11392 KB Output is correct
15 Correct 11 ms 11392 KB Output is correct
16 Correct 11 ms 11392 KB Output is correct
17 Correct 13 ms 11520 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 11 ms 11392 KB Output is correct
22 Correct 11 ms 11392 KB Output is correct
23 Correct 25 ms 12928 KB Output is correct
24 Correct 26 ms 12940 KB Output is correct
25 Correct 28 ms 13176 KB Output is correct
26 Correct 44 ms 14720 KB Output is correct
27 Correct 56 ms 14704 KB Output is correct
28 Correct 45 ms 14840 KB Output is correct
29 Correct 41 ms 14712 KB Output is correct
30 Correct 41 ms 14840 KB Output is correct
31 Correct 45 ms 15096 KB Output is correct

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 11 ms 11264 KB Output is correct
6 Correct 11 ms 11264 KB Output is correct
7 Correct 12 ms 11264 KB Output is correct
8 Correct 11 ms 11272 KB Output is correct
9 Correct 12 ms 11264 KB Output is correct
10 Correct 11 ms 11264 KB Output is correct
11 Correct 12 ms 11264 KB Output is correct
12 Correct 11 ms 11344 KB Output is correct
13 Correct 12 ms 11308 KB Output is correct
14 Correct 11 ms 11392 KB Output is correct
15 Correct 11 ms 11392 KB Output is correct
16 Correct 11 ms 11392 KB Output is correct
17 Correct 13 ms 11520 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 11 ms 11392 KB Output is correct
22 Correct 11 ms 11392 KB Output is correct
23 Correct 25 ms 12928 KB Output is correct
24 Correct 26 ms 12940 KB Output is correct
25 Correct 28 ms 13176 KB Output is correct
26 Correct 44 ms 14720 KB Output is correct
27 Correct 56 ms 14704 KB Output is correct
28 Correct 45 ms 14840 KB Output is correct
29 Correct 41 ms 14712 KB Output is correct
30 Correct 41 ms 14840 KB Output is correct
31 Correct 45 ms 15096 KB Output is correct
32 Correct 368 ms 28412 KB Output is correct
33 Correct 327 ms 28536 KB Output is correct
34 Correct 317 ms 28408 KB Output is correct
35 Execution timed out 1074 ms 79716 KB Time limit exceeded
36 Halted 0 ms 0 KB -