Submission #94921

#	Time	Username	Problem	Language	Result	Execution time	Memory
94921		Retro3014	Training (IOI07_training)	C++17	30 / 100	4 ms	632 KiB

training

#include <iostream>
#include <algorithm>
#include <vector>
#include <stdio.h>

#define MAX_N 1000
using namespace std;

int N, M;
struct S{
	int idx, data;
};
struct E{
	int x, y, z;
};

vector<E> e;
vector<int> gp[MAX_N+1];
vector<E> gp2[MAX_N+1];

int p[MAX_N+1][15];
int c[MAX_N+1];
int lv[MAX_N+1];
int ans;
int dp[MAX_N+1];



void dfs(int x){
	for(int i=1; i<15; i++){
		p[x][i] = p[p[x][i-1]][i-1];
	}
	for(int i=0; i<gp[x].size(); i++){
		if(c[gp[x][i]]==0){
			c[gp[x][i]] = 3 - c[x];
			p[gp[x][i]][0] = x;
			lv[gp[x][i]] = lv[x] + 1;
			dfs(gp[x][i]);
		}
	}
}

int up(int x, int y){
	int two = (1<<14);
	for(int i=14; i>=0; i--){
		if(y>=two){
			x = p[x][i];
			y-=two;
		}
		two/=2;
	}
	return x;
}

int lca(int x, int y){
	if(lv[x]>lv[y]){
		x = up(x, lv[x]-lv[y]);
	}
	if(lv[x]<lv[y]){
		y = up(y, lv[y]-lv[x]);
	}
	if(x==y)	return x;
	for(int i=14; i>=0; i--){
		if(p[x][i]!=p[y][i]){
			x = p[x][i]; y = p[y][i];
		}
	}
	if(x==y)	return x;
	return p[x][0];
}

void dfs2(int x){
	dp[x] = 0;
	for(int i=0; i<gp[x].size(); i++){
		if(gp[x][i]!=p[x][0]){
			dfs2(gp[x][i]);
			dp[x]+=dp[gp[x][i]];
		}
	}
	for(int i=0; i<gp2[x].size(); i++){
		int k = 0, pp1, pp2;
		E now = gp2[x][i];
		if(now.y==x){int tmp = now.x; now.x = now.y; now.y = tmp;}
		if(now.x==x){
			pp1 = up(now.y, lv[now.y]-lv[x]-1);
			k = now.z + dp[now.y];
			for(int j=0; j<gp[x].size(); j++){
				if(gp[x][j]!=p[x][0] && gp[x][j]!=pp1){
					k+=dp[gp[x][j]];
				}
			}
		}else{
			pp1 = up(now.x, lv[now.x]-lv[x]-1); pp2 = up(now.y, lv[now.y]-lv[x]-1);
			k = now.z + dp[now.x] + dp[now.y];
			for(int j=0; j<gp[x].size(); j++){
				if(gp[x][j]!=p[x][0] && gp[x][j]!=pp1 && gp[x][j]!=pp2){
					k+=dp[gp[x][j]];
				}
			}
		}
		dp[x] = max(dp[x], k);
	}
	return;
}

int degree[MAX_N+1];

int main(){
	scanf("%d%d", &N, &M);

	for(int i=0; i<M; i++){
		int a, b, c;
		scanf("%d%d%d", &a, &b, &c);
		if(c==0){
			degree[a]++; degree[b]++;
			gp[a].push_back(b); gp[b].push_back(a);
		}else{
			e.push_back({a, b, c});
			ans+=c;
		}
	}
	int now=1;
	c[now] = 1;
	lv[now] = 1;
	dfs(now);	
	for(int i=0; i<e.size(); i++){
		if(c[e[i].x]==c[e[i].y]){
			gp2[lca(e[i].x, e[i].y)].push_back(e[i]);
		}
	}
	dfs2(now);
	ans-=dp[now];
	printf("%d", ans);
	return 0;
}

Compilation message (stderr)

training.cpp: In function 'void dfs(int)':
training.cpp:33:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i=0; i<gp[x].size(); i++){
               ~^~~~~~~~~~~~~
training.cpp: In function 'void dfs2(int)':
training.cpp:74:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i=0; i<gp[x].size(); i++){
               ~^~~~~~~~~~~~~
training.cpp:80:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i=0; i<gp2[x].size(); i++){
               ~^~~~~~~~~~~~~~
training.cpp:87:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
    for(int j=0; j<gp[x].size(); j++){
                 ~^~~~~~~~~~~~~
training.cpp:95:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
    for(int j=0; j<gp[x].size(); j++){
                 ~^~~~~~~~~~~~~
training.cpp: In function 'int main()':
training.cpp:126:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i=0; i<e.size(); i++){
               ~^~~~~~~~~
training.cpp:109:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d%d", &N, &M);
  ~~~~~^~~~~~~~~~~~~~~~
training.cpp:113:8: 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: 10 / 10
• Subtask 2: 10 / 10
• Subtask 3: 10 / 10
• Subtask 4: 0 / 7
• Subtask 5: 0 / 9
• Subtask 6: 0 / 9
• Subtask 7: 0 / 9
• Subtask 8: 0 / 9
• Subtask 9: 0 / 9
• Subtask 10: 0 / 9
• Subtask 11: 0 / 9