【HDOJ】1987 Decoding

简单搜索。

/* hdoj 1987 */
#include <iostream>
#include <cstdio>
#include <cstring>
#include <cstdlib>
#include <algorithm>
using namespace std;

char s[505];
char map[25][25];
bool visit[25][25];
int n, m, len;
int dir[4][2] = {
    0,1, 1,0, 0,-1, -1,0
}; // right down left up

bool check(int x, int y) {
    return x<0 || x>=n || y<0 || y>=m;
}

void solve() {
    int i, j, k, tmp;
    int d = 0;
    int t = n*m/5;
    int x, y, xx, yy;
    
    len = 0;
    memset(visit, false, sizeof(visit));
    
    x = 0, y = -1;
    while (t--) {
        k = 5;
        tmp = 0;
        while (k) {
            xx = x + dir[d][0];
            yy = y + dir[d][1];
            if (check(xx, yy) || visit[xx][yy]) {
                d = (d+1) & 3;
                continue;
            }
            visit[xx][yy] = true;
            tmp = (tmp<<1) + map[xx][yy]-'0';
            --k;
            x = xx;
            y = yy;
        }
        if (tmp == 0)
            s[len++] = ' ';
        else
            s[len++] = tmp + 'A' - 1;
    }
}

int main() {
    int t, tt;
    int i, j, k;
    
    #ifndef ONLINE_JUDGE
        freopen("data.in", "r", stdin);
    #endif
    
    scanf("%d", &t);
    for (tt=1; tt<=t; ++tt) {
        scanf("%d %d %s", &n, &m, s);
        k = 0;
        for (i=0; i<n; ++i)
            for (j=0; j<m; ++j)
                map[i][j] = s[k++];
        solve();
        i = len - 1;
        while (s[i] == ' ')
            --i;
        s[i+1] = '';
        i = 0;
        while (s[i] == ' ')
            ++i;
        printf("%d %s
", tt, s+i);
    }
    
    return 0;
}