HDU 1253 (简单三维广搜) 胜利大逃亡
奇葩！这么简单的广搜居然爆内存了，而且一直爆，一直爆，Orz
而且我也优化过了的啊，尼玛还是一直爆！
先把代码贴上睡觉去了，明天再来弄
1 //#define LOCAL 2 #include <iostream> 3 #include <cstdio> 4 #include <cstring> 5 #include <queue> 6 #include <cmath> 7 using namespace std; 8 9 struct Point 10 { 11 int x, y, z; 12 int steps; 13 }start; 14 15 int a, b, c, m; 16 int map[52][52][52]; 17 int dir[6][3] = {{1,0,0}, {-1,0,0}, {0,1,0}, {0,-1,0}, {0,0,1}, {0,0,-1}}; 18 19 bool islegal(int x, int y, int z) 20 { 21 return (x>=0 && x<a && y>=0 && y<b && z>=0 && z<c && (map[x][y][z] == 0)); 22 } 23 24 void BFS(void) 25 { 26 queue<Point> qu; 27 start.x = start.y = start.z = start.steps = 0; 28 map[0][0][0] = 1; 29 qu.push(start); 30 while(!qu.empty()) 31 { 32 Point fir = qu.front(); 33 qu.pop(); 34 if(fir.x==a-1 && fir.y==b-1 && fir.z==c-1) 35 {printf("%d\n", fir.steps); return;} 36 if(fir.steps > m) 37 {printf("-1\n"); return;} 38 for(int i = 0; i < 6; ++i) 39 { 40 int xx = fir.x + dir[i][0]; 41 int yy = fir.y + dir[i][1]; 42 int zz = fir.z + dir[i][2]; 43 if(islegal(xx, yy, zz)) 44 { 45 Point next; 46 next.x = xx, next.y = yy, next.z = zz; 47 next.steps = fir.steps + 1; 48 map[zz][xx][yy] = 1; 49 if(abs(xx-a+1)+abs(yy-b+1)+abs(zz-c+1)+next.steps > m) 50 continue; 51 qu.push(next); 52 } 53 } 54 } 55 printf("-1\n"); 56 } 57 58 int main(void) 59 { 60 #ifdef LOCAL 61 freopen("1253in.txt", "r", stdin); 62 #endif 63 64 int T; 65 scanf("%d", &T); 66 while(T--) 67 { 68 scanf("%d%d%d%d", &a, &b, &c, &m); 69 for(int i = 0; i < a; ++i) 70 for(int j = 0; j < b; ++j) 71 for(int k = 0; k < c; ++k) 72 scanf("%d", &map[i][j][k]); 73 74 BFS(); 75 } 76 return 0; 77 }
最终还是自己用数组模拟队列A过去了
一个优化：
因为题目要求在规定时间内走出迷宫，如果出口距离当前位置太远(即使在没有墙壁阻挡的情况下也走不到)，那么就可以直接输出-1了
这个优化让900+MS的运行时间减少到了500+MS，还是比较给力的
1 //#define LOCAL 2 #include <iostream> 3 #include <cstdio> 4 #include <cstring> 5 using namespace std; 6 7 const int maxn = 50*50*50+100; 8 int head, tail; 9 struct Point 10 { 11 int x, y, z; 12 int steps; 13 }qu[maxn]; 14 15 int a, b, c, m; 16 int map[52][52][52]; 17 int dir[6][3] = {{1,0,0}, {-1,0,0}, {0,1,0}, {0,-1,0}, {0,0,1}, {0,0,-1}}; 18 19 bool islegal(int x, int y, int z) 20 { 21 return (x>=0 && x<a && y>=0 && y<b && z>=0 && z<c && (map[x][y][z] == 0)); 22 } 23 24 void BFS(void) 25 { 26 qu[0].x = qu[0].y = qu[0].z = qu[0].steps = 0; 27 head = 0, tail = 1; 28 while(head < tail) 29 { 30 if(qu[head].steps > m) 31 {printf("-1\n"); return;} 32 if(qu[head].x==a-1 && qu[head].y==b-1 && qu[head].z==c-1) 33 {printf("%d\n", qu[head].steps); return;} 34 for(int i = 0; i < 6; ++i) 35 { 36 int xx = qu[head].x + dir[i][0]; 37 int yy = qu[head].y + dir[i][1]; 38 int zz = qu[head].z + dir[i][2]; 39 if(islegal(xx, yy, zz)) 40 { 41 map[xx][yy][zz] = 1; 42 if(a+b+c-3-xx-yy-zz > m-qu[head].steps-1) //优化 43 continue; 44 qu[tail].x = xx; 45 qu[tail].y = yy; 46 qu[tail].z = zz; 47 qu[tail++].steps = qu[head].steps + 1; 48 } 49 } 50 ++head; 51 } 52 printf("-1\n"); 53 } 54 55 int main(void) 56 { 57 #ifdef LOCAL 58 freopen("1253in.txt", "r", stdin); 59 #endif 60 61 int T; 62 scanf("%d", &T); 63 while(T--) 64 { 65 scanf("%d%d%d%d", &a, &b, &c, &m); 66 for(int i = 0; i < a; ++i) 67 for(int j = 0; j < b; ++j) 68 for(int k = 0; k < c; ++k) 69 scanf("%d", &map[i][j][k]); 70 71 //map[0][0][0] = 1; 72 BFS(); 73 } 74 return 0; 75 }
