A. The Fault in Our Cubes 暴力dfs

http://codeforces.com/gym/101257/problem/A

把它固定在（0，0, 0）到（2， 2， 2）上，每次都暴力dfs检查，不会超时的，因为规定在这个空间上，一不行，就会早早退出。

这样写起来比较好写。

#include <cstdio>

#include <cstdlib>

#include <cstring>

#include <cmath>

#include <algorithm>

#include <assert.h>

#define IOS ios::sync_with_stdio(false)

using namespace std;

#define inf (0x3f3f3f3f)

typedef long long int LL;

#include <iostream>

#include <sstream>

#include <vector>

#include <set>

#include <map>

#include <queue>

#include <string>

#include <bitset>

const int maxn =  + ;

bool vis[][][];

char str[maxn];

int fx[] = {, , , -, , };

int fy[] = {, , -, , , };

int fz[] = {, , , , -, };

bool check(int x, int y, int z) {

    if (x <  || y <  || z < ) return false;

    if (x >  || y >  || z > ) return false;

    if (vis[x][y][z]) return false;

    return true;

}

int op[];

bool dfs(int cur, int x, int y, int z, int dir) {

    int tx = fx[dir] + x, ty = fy[dir] + y, tz = fz[dir] + z;

    if (cur == ) {

        if (check(tx, ty, tz)) return true;

        else return false;

    }

    if (!check(tx, ty, tz)) return false;

    if (str[cur] == 'I') {

        vis[tx][ty][tz] = true;

        if (dfs(cur + , tx, ty, tz, dir)) {

            return true;

        } else {

            vis[tx][ty][tz] = false;

            return false;

        }

    } else {

        vis[tx][ty][tz] = true;

        for (int i = ; i < ; ++i) {

            if (dir == i || op[dir] == i) continue;

            if (dfs(cur + , tx, ty, tz, i)) {

                return true;

            }

        }

        vis[tx][ty][tz] = false;

        return false;

    }

}

void work() {

    op[] = ;

    op[] = ;

    op[] = ;

    op[] = ;

    op[] = ;

    op[] = ;

    scanf("%s", str + );

    for (int i = ; i <= ; ++i) {

        if (str[i] == 'E') {

            cout << "NO" << endl;

            return;

        }

    }

    for (int i = ; i < ; ++i) {

        for (int j = ; j < ; ++j) {

            for (int k = ; k < ; ++k) {

                vis[i][j][k] = true;

                if (dfs(, i, j, k, )) {

                    cout << "YES" << endl;

                    return;

                }

                vis[i][j][k] = false;

            }

        }

    }

    cout << "NO" << endl;

}

int main() {

#ifdef local

    freopen("data.txt", "r", stdin);

//    freopen("data.txt", "w", stdout);

#endif

    work();

    return ;

}