Submission #133717

#	Time	Username	Problem	Language	Result	Execution time	Memory
133717		tinjyu	Race (IOI11_race)	C++14	31 / 100	341 ms	181212 KiB

race

#include "race.h"
#include <iostream>
using namespace std;
int tag[200005],road[200005],map[400005][3],t[100000][2],n,k;
int a=10000000,ans[200005][205];
int find(int x)
{
	tag[x]=1;
	int g=road[x];
	//cout<<x<<endl;
	while(g!=-1)
	{
		int now=map[g][0];
		if(tag[now]!=1)
		{
			find(now);
			//cout<<x<<" "<<now<<endl;
			for(int i=map[g][2];i<=k;i++)
			{
				a=min(ans[now][i-map[g][2]]+ans[x][k-i]+1,a);
				//cout<<ans[now][i-map[g][2]]<<" "<<ans[x][k-i]<<" "<<k-i-map[g][2]<<"  ";
				
			}
			//cout<<endl;
			for(int i=0;i<=k-map[g][2];i++)ans[x][i+map[g][2]]=min(ans[now][i]+1,ans[x][i+map[g][2]]);
		}
		g=map[g][1];
	}
}
int best_path(int N, int K, int H[][2], int L[])
{
	n=N,k=K;
	for(int i=0;i<n;i++)
	{
		for(int j=1;j<=k;j++)ans[i][j]=10000000;
	}
	
	for(int i=0;i<n;i++)
	{
		road[i]=-1;
	}
	for(int i=0;i<n-1;i++)
	{
		int x=H[i][0],y=H[i][1];
		map[i*2][0]=y;
		map[i*2][1]=road[x];
		map[i*2][2]=L[i];
		road[x]=i*2;
		map[i*2+1][0]=x;
		map[i*2+1][1]=road[y];
		map[i*2+1][2]=L[i];
		road[y]=i*2+1;
	}
	if(k<=100)
	{
		find(0);
		for(int i=0;i<n;i++)a=min(ans[i][k],a);
		if(a==10000000)a=-1;
  		return a;
  	}
  	else
  	{
  		for(int i=0;i<n;i++)
		{
			for(int j=0;j<n;j++)tag[j]=0;
			int p=0,pp=0;
			t[0][0]=i;
			t[0][1]=0;
			t[0][2]=0;
			tag[i]=1;
			while(p<=pp)
			{
				int x=t[p][0];
				int g=road[x];
				while(g!=-1)
				{
					int now=map[g][0];
					if(tag[now]==0)
					{
						tag[now]=1;
						pp++;
						t[pp][0]=now;
						t[pp][1]=t[p][1]+map[g][2];
						t[pp][2]=t[p][2]+1;
						if(t[pp][1]==k)
						{
							a=min(a,t[pp][2]);
							//cout<<now<<t<<endl;
						}
					}
					g=map[g][1];
				}
				p++;
			}
		}
		if(a==10000000)a=-1;
 	 	return a;
	}
}

Compilation message (stderr)

race.cpp: In function 'int find(int)':
race.cpp:29:1: warning: no return statement in function returning non-void [-Wreturn-type]
 }
 ^
race.cpp: In function 'int best_path(int, int, int (*)[2], int*)':
race.cpp:69:10: warning: array subscript is above array bounds [-Warray-bounds]
    t[0][2]=0;
    ~~~~~~^
race.cpp:84:22: warning: array subscript is above array bounds [-Warray-bounds]
       t[pp][2]=t[p][2]+1;
                ~~~~~~^
race.cpp:84:14: warning: array subscript is above array bounds [-Warray-bounds]
       t[pp][2]=t[p][2]+1;
       ~~~~~~~^

• Subtask 1: 9 / 9
• Subtask 2: 0 / 12
• Subtask 3: 22 / 22
• Subtask 4: 0 / 57