poj 1979 迷宫搜索

#include <stdio.h>
#include <string.h>
#define N 23
char s

;
int flag

,q[N*N][2];//flag为标记数组，搜索到的区域标记为1
int round[4][2] = {-1,0,0,1,1,0,0,-1};
int n,m;
int check(int x,int y){
if(x<0||y<0||x>=n||y>=m)
return 0;
if(flag[x][y] || s[x][y]!='.')
return 0;
return 1;
}
void bfs(int x,int y){
int front,rear,i;
front = rear = -1;
q[++rear][0] = x;
q[rear][1] = y;
while(front < rear){
int nowx = q[++front][0];
int nowy = q[front][1];
for(i = 0;i<4;i++){
int xx = nowx+round[i][0];
int yy = nowy+round[i][1];
if(check(xx,yy)){
q[++rear][0] = xx;
q[rear][1] = yy;
flag[xx][yy] = 1;
}
}
}
}
int main(){
freopen("a.txt","r",stdin);
while(scanf("%d %d",&m,&n) &&n &&m){
int i,j,x,y,sum = 0;
memset(flag,0,sizeof(flag));
for(i = 0;i<n;i++){
scanf("%s",s[i]);
for(j = 0;j<m;j++)
if(s[i][j] == '@'){
x = i;
y = j;
}
}
flag[x][y] = 1;
bfs(x,y);
for(i = 0;i<n;i++)
for(j = 0;j<m;j++)
sum += flag[i][j];
printf("%d\n",sum);
}
return 0;
}

#include <stdio.h>
#include <string.h>
int m,n;
int x,y;
char s[23][23];
int flag[23][23];
int around[4][2] = {
{-1,0},{0,-1},{1,0},{0,1}
};
int dfs(int x,int y){
int i,sum = 0;
flag[x][y] = 0;
for(i = 0;i<4;i++){
int xx = x+around[i][0];
int yy = y+around[i][1];
if(flag[xx][yy])
sum += dfs(xx,yy);
}
return sum+1;
}
int main(){
freopen("a.txt","r",stdin);
while(scanf("%d %d",&m,&n) && n && m){
int i,j;
memset(flag,0,sizeof(flag));
for(i = 1;i<=n;i++){
getchar();
for(j=1;j<=m;j++){
s[i][j] = getchar();
if(s[i][j] == '.')
flag[i][j] = 1;
if(s[i][j] == '@'){
x = i;
y = j;
}
}
}
printf("%d\n",dfs(x,y));
}
}