Submission #152006

#	Time	Username	Problem	Language	Result	Execution time	Memory
152006		TadijaSebez	Robots (APIO13_robots)	C++11	100 / 100	858 ms	138676 KiB

robots

#include <bits/stdc++.h>
using namespace std;
#define pb push_back
const int N=501;
const int H=500*500+1;
const int inf=1e9+7;
int n,m,k,nm;
int ID(int x, int y){ return (x-1)*m+y;}
int go[N][N][4],Move[4][2]={{0,1},{-1,0},{0,-1},{1,0}};
char base[N][N];
int Get(int x, int y, int d)
{
	if(base[x][y]=='x' || x==0 || y==0 || x>n || y>m) return ID(x-Move[d][0],y-Move[d][1]);
	if(go[x][y][d]) return go[x][y][d];
	go[x][y][d]=-1;
	if(base[x][y]=='A') go[x][y][d]=Get(x+Move[(d+1)%4][0],y+Move[(d+1)%4][1],(d+1)%4);
	else if(base[x][y]=='C') go[x][y][d]=Get(x+Move[(d+3)%4][0],y+Move[(d+3)%4][1],(d+3)%4);
	else go[x][y][d]=Get(x+Move[d][0],y+Move[d][1],d);
	return go[x][y][d];
}
vector<int> E[H];
int dist[10][10][H];
void BFS(int st, int id)
{
	queue<int> q;
	for(int i=1;i<=nm;i++) dist[id][id][i]=-1;
	dist[id][id][st]=0;
	q.push(st);
	while(q.size())
	{
		int x=q.front();
		q.pop();
		for(int y:E[x]) if(dist[id][id][y]==-1)
		{
			dist[id][id][y]=dist[id][id][x]+1;
			q.push(y);
		}
	}
	for(int i=1;i<=nm;i++) if(dist[id][id][i]==-1) dist[id][id][i]=inf;
}
int tmp_d[H];
vector<int> q[H*10];
void Dijkstra()
{
	int mn=inf,work=0;
	for(int i=1;i<=nm;i++) if(tmp_d[i]!=inf) q[tmp_d[i]].pb(i),mn=min(mn,tmp_d[i]),work++;
	for(int ptr=mn;ptr<H*10 && work>0;ptr++)
	{
		while(q[ptr].size())
		{
			int x=q[ptr].back();
			q[ptr].pop_back();
			if(ptr!=tmp_d[x]) continue;
			work--;
			for(int y:E[x]) if(tmp_d[y]>tmp_d[x]+1)
			{
				tmp_d[y]=tmp_d[x]+1;
				if(tmp_d[y]>=H*10) continue;
				q[tmp_d[y]].pb(y);
				work++;
			}
		}
	}
}
int main()
{
	scanf("%i %i %i",&k,&m,&n);nm=n*m;
	for(int i=1;i<=n;i++) scanf("%s",base[i]+1);
	for(int i=1;i<=n;i++) for(int j=1;j<=m;j++)
	{
		for(int d=0;d<4;d++)
		{
			if(Get(i,j,d)!=-1) E[ID(i,j)].pb(go[i][j][d]);
		}
	}
	for(int i=1;i<=n;i++) for(int j=1;j<=m;j++) if(base[i][j]>='1' && base[i][j]<='9')
	{
		int id=base[i][j]-'0';
		BFS(ID(i,j),id);
	}
	for(int len=2;len<=k;len++) for(int i=1;i<=k-len+1;i++)
	{
		int j=i+len-1;
		for(int u=1;u<=nm;u++) dist[i][j][u]=inf;
		for(int z=i;z<j;z++)
		{
			for(int u=1;u<=nm;u++) if(dist[i][z][u]!=-1 && dist[z+1][j][u]!=-1)
			{
				int sum=dist[i][z][u]+dist[z+1][j][u];
				if(dist[i][j][u]==-1 || sum<dist[i][j][u]) dist[i][j][u]=sum;
			}
		}
		for(int u=1;u<=nm;u++) tmp_d[u]=dist[i][j][u];
		Dijkstra();
		for(int u=1;u<=nm;u++) dist[i][j][u]=tmp_d[u];
	}
	int ans=-1;
	for(int u=1;u<=nm;u++) if(dist[1][k][u]!=inf)
	{
		if(ans==-1 || ans>dist[1][k][u]) ans=dist[1][k][u];
	}
	printf("%i\n",ans);
	return 0;
}

Compilation message (stderr)

robots.cpp: In function 'int main()':
robots.cpp:67:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%i %i %i",&k,&m,&n);nm=n*m;
  ~~~~~^~~~~~~~~~~~~~~~~~~~~
robots.cpp:68:29: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  for(int i=1;i<=n;i++) scanf("%s",base[i]+1);
                        ~~~~~^~~~~~~~~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 20 / 20
• Subtask 3: 30 / 30
• Subtask 4: 40 / 40