【暑假复习】【搜索】AOJ0558:Cheese

题意

题解

#include<cstdio>
#include<algorithm>
#include<cstring>
#include<queue>
#define SF scanf
#define PF printf
#define PII pair<int,int>
#define MAXN 1010
#define MAXM 20
using  namespace std;
int n,m,cnt,time,ma[MAXN][MAXN],w[4][2]={{1,0},{-1,0},{0,1},{0,-1}};
PII num[MAXM];
queue<PII > q;
int vis[MAXN][MAXN];
char c;
void read(){
SF("%d%d%d",&n,&m,&cnt);
for(int i=1;i<=n;i++){
SF("\n");
for(int j=1;j<=m;j++){
SF("%c",&c);
if(c=='X')
ma[i][j]=1;
else if(c=='S')
num[0]=make_pair(i,j);
else if(c>='1'&&c<='9')
num[c-'0']=make_pair(i,j);
}
}
}
int check(int x,int y){
if(x*y==0||x>n||y>m)
return 0;
if(vis[x][y]!=0||ma[x][y]!=0)
return 0;
return 1;
}
int ask(int stx,int sty,int edx,int edy){
while(!q.empty())
q.pop();
memset(vis,0,sizeof vis);
q.push(make_pair(stx,sty));
vis[stx][sty]=1;
while(!q.empty()){
PII nex=q.front();
q.pop();
int x=nex.first;
int y=nex.second;
//PF("(%d %d %d)\n",x,y,ma[x][y]);
if(x==edx&&y==edy)
return vis[x][y]-1;
for(int i=0;i<4;i++){
int x1=x+w[i][0];
int y1=y+w[i][1];
if(check(x1,y1)){
q.push(make_pair(x1,y1));
vis[x1][y1]=vis[x][y]+1;
}
}
}

}
int main(){
read();
for(int i=1;i<=cnt;i++)
time+=ask(num[i-1].first,num[i-1].second,num[i].first,num[i].second);
PF("%d\n",time);
}