UVa 657 The die is cast（DFS）

双层DFS， X数量绝对不超过6个，所以毫无疑问，双层就可以解决掉！

#include <cstdio>
#include <cstring>
#include <iostream>
#include <algorithm>
using namespace std;

const int N = 55;
int n, m, numx, cnt, ans[N*N];
int a[] = { 0, 0, 1, -1 };
int b[] = { 1, -1, 0, 0 };
char g

;

void dfsx ( int x, int y ) {
g[x][y] = '*';
for ( int i = 0; i < 4; ++i ) {
int xx = x + a[i], yy = y + b[i];
if ( g[xx][yy] == 'X' ) dfsx( xx, yy );
}
}
void dfs( int x, int y ) {
if ( g[x][y] == 'X' ) {
numx++;
dfsx ( x, y );
}
g[x][y] = '.';
for ( int i = 0; i < 4; ++i ) {
int xx = x + a[i], yy = y + b[i];
if ( g[xx][yy] == 'X' || g[xx][yy] == '*' ) dfs( xx, yy );
}
}
int main()
{
int icase = 1;
while ( scanf("%d%d", &m, &n) != EOF && ( n || m ) ) {
memset( g, '\0', sizeof(g) );
memset( ans, 0, sizeof(ans) );
cnt = 0;
for ( int i = 0; i < n; ++i )
scanf("%s", g[i]);
for ( int i = 0; i < n; ++i )
for ( int j = 0; j < m; ++j ) {
if ( g[i][j] == 'X' || g[i][j] == '*' ) {
numx = 0;
dfs( i, j );
ans[cnt++] = numx;
}
}
sort( ans, ans + cnt );
printf("Throw %d\n%d", icase++, ans[0]);
for ( int i = 1; i < cnt; ++i ) printf(" %d", ans[i]);
printf("\n\n");
}
}