hdu 1495 非常可乐（bfs）

题目链接 http://acm.hdu.edu.cn/showproblem.php?pid=1495

题意就不解释了。

总之这很暴力，就6种倒法

(1)s != 0 , s->n;

(2)s != 0 , s->m;

(3)n != 0 , n->s;

(4)n != 0 , n->m;

(5)m != 0 , m->n;

(6)m != 0 , m->s;

bfs一遍就好了。

#include <iostream>
#include <cstring>
#include <cstdio>
#include <algorithm>
#include <queue>
#define inf 0X3f3f3f3f
using namespace std;
int s , n , m , ans , vis[110][110][110];
struct TnT {
    int x , y , z , step;
};
int bfs(int xx , int yy , int zz , int step) {
    memset(vis , 0 , sizeof(vis));
    TnT g;
    g.x = xx , g.y = yy , g.z = zz , g.step = step;
    queue<TnT>q;
    q.push(g);
    vis[xx][yy][zz] = 1;
    while(!q.empty()) {
        TnT gg = q.front();
        int x = gg.x , y = gg.y , z = gg.z;
        if((x == y && x == s / 2) || (x == z && x == s / 2) || (z == y && z == s / 2)) {
            return gg.step;
        }
        if(x != 0) {
            if(y != n && !vis[max(0 , x - (n - y))][min(n , y + x)][z]) {
                TnT gl = gg;
                gl.x = max(0 , x - (n - y)) , gl.y = min(n , y + x) , gl.z = z , gl.step++;;
                vis[max(0 , x - (n - y))][min(n , y + x)][z] = 1;
                q.push(gl);
            }
            if(z != m && !vis[max(0 , x - (m - z))][y][min(m , z + x)]) {
                TnT gl = gg;
                gl.x = max(0 , x - (m - z)) , gl.y = y , gl.z = min(m , z + x) , gl.step++;
                vis[max(0 , x - (m - z))][y][min(m , z + x)] = 1;
                q.push(gl);
            }
        }
        if(y != 0) {
            if(x != s && !vis[min(s , x + y)][max(0 , y - (s - x))][z]) {
                TnT gl = gg;
                gl.x = min(s , x + y) , gl.y = max(0 , y - (s - x)) , gl.z = z , gl.step++;;
                vis[min(s , x + y)][max(0 , y - (s - x))][z] = 1;
                q.push(gl);
            }
            if(z != m && !vis[x][max(0 , y - (m - z))][min(m , z + y)]) {
                TnT gl = gg;
                gl.x = x , gl.y = max(0 , y - (m - z)) , gl.z = min(m , z + y) , gl.step++;
                vis[x][max(0 , y - (m - z))][min(m , z + y)] = 1;
                q.push(gl);
            }
        }
        if(z != 0) {
            if(x != s && !vis[min(s , x + z)][y][max(0 , z - (s - x))]) {
                TnT gl = gg;
                gl.x = min(s , x + z) , gl.y = y , gl.z = max(0 , z - (s - x)) , gl.step++;
                vis[min(s , x + z)][y][max(0 , z - (s - x))] = 1;
                q.push(gl);
            }
            if(y != n && !vis[x][min(n , y + z)][max(0 , z - (n - y))]) {
                TnT gl = gg;
                gl.x = x , gl.y = min(n , y + z) , gl.z = max(0 , z - (n - y)) , gl.step++;
                vis[x][min(n , y + z)][max(0 , z - (n - y))] = 1;
                q.push(gl);
            }
        }
        q.pop();
    }
    return -1;
}
int main()
{
    while(scanf("%d%d%d" , &s , &n , &m) != EOF) {
        if(s == 0) {
            break;
        }
        if(s % 2 != 0) {
            printf("NO
");
            continue;
        }
        else {
            int a[3];
            memset(vis , 0 , sizeof(vis));
            a[0] = s , a[1] = n , a[2] = m;
            sort(a , a + 3);
            s = a[2] , n = a[1] , m = a[0];
            ans = bfs(s , 0 , 0 , 0);
            if(ans != -1)
                printf("%d
" , ans);
            else {
                printf("NO
");
            }
        }
    }
    return 0;
}