zoj2110Tempter of the Bone

#include <iostream>#include <cstdio>#include <cstring>#include <cmath>using namespace std;int d[4][2] = {{0, -1}, {-1, 0}, {0, 1}, {1, 0} };int N, M, T;char map1[10][10];int flag[10][10];int sx, sy, ex, ey;bool res;///represent the resultint wall;void input_map() {    char tmp;///吃掉回车符。    for(int i = 1; i <= N; i++) {        for(int j = 1; j <= M; j++) {            scanf("%c", &map1[i][j]);            if(map1[i][j] == 'S') { sx = i; sy = j; }            if(map1[i][j] == 'D') { ex = i, ey = j; }            if(map1[i][j] == 'X') { wall++; }        }        scanf("%c", &tmp);    }}void dfs(int x, int y, int t) {  //  cout << x << ' ' << y << ' ' << t << endl;    if(map1[x][y] == 'X') {        return;    }    else  if(x == ex && y == ey&& t == T) {        res = true; return;    }    int temp = (T-t) - fabs(x-ex) - fabs(y-ey);    if(temp < 0 || temp%2) { return; }      //剪枝    int nx, ny;    map1[x][y] = 'D';///mark    flag[x][y] = 1;    for(int i = 0; i < 4; i++) {        nx = x + d[i][0];        ny = y + d[i][1];        if(map1[nx][ny] != 'X' && flag[nx][ny] == 0 ) {///是否可行且访问过。            if(nx >= 1 && nx <= N && ny >= 1 && ny <= M) {///是否越界                if(res) { return ;}//剪枝                dfs(nx, ny, t+1);            }        }    }    map1[x][y] = '.';    flag[x][y] = 0;    return ;}int main() {    while(scanf("%d%d%d", &N, &M, &T) != EOF) {        if(!N && !M && !T) { break; }        res = false;///init false;        memset(flag, 0, sizeof(flag));        wall = 0;///init;        char tmp;        scanf("%c", &tmp);///吃掉回车符。        input_map();        if(N*M - wall <= T) {            cout << "NO" << endl;            continue;        }        dfs(sx, sy, 0);        if(res) {            cout << "YES" << endl;        }        else {            cout << "NO" << endl;        }    }    return 0;}/************************3 4 5S....X.X...D4 4 8.X.X..S.....DX.X4 4 5S.X...X...XD....http://acm.zju.edu.cn/onlinejudge/showProblem.do?problemId=1110***************************/