标签:style blog color os io for div log sp
刚开始想 stl水过去 ,一直超时。坑的是 这题贪吃蛇,头不能向尾部移动,后来手跑了样例才发现。。
二进制位压判重,然后就普通的bfs 搞。对于那些30ms 过的很ym。。
#include <cstdio> #include <cstring> #include <algorithm> #include <climits> #include <string> #include <iostream> #include <map> #include <cstdlib> #include <list> #include <set> #include <queue> #include <stack> #include<math.h> using namespace std; int dx[] = { -1, 1, 0, 0 }; int dy[] = { 0, 0, -1, 1 }; int n, m, l; bool vis[21][21][1 << 14]; int dis[40][40]; int Map[40][40]; const int maxn = 1111111; int xxx[maxn]; int yyy[maxn]; int st[maxn]; int q[maxn]; int gao(int state, int x, int y, int x2, int y2) { int xiaojiji; if (x2 >= 1 && x2 <= n&&y2 >= 1 && y2 <= m&&!Map[x2][y2]) xiaojiji = 1; else return 0; int x1 = x; int y1 = y; for (int i = 0; i < l - 1; i++){ int pos = i * 2; int a = state&(1 << pos); int b = state&(1 << (pos + 1)); if (a) a = 1; if (b) b = 1; int t = b * 2 + a; x1 = x1 + dx[t]; y1 = y1 + dy[t]; if (x1 == x2&&y1 == y2) return 0; } return 1; } int gao1(int state, int x, int y, int x2, int y2) { int gg = state; gg &= ~(1 << ((l - 1) * 2 - 1)); gg &= ~(1 << ((l - 1) * 2 - 2)); gg <<= 2; if (x - x2 == 1) gg |= 1; if (y - y2 == -1) gg |= 2; if (y - y2 == 1) gg |= 1, gg |= 2; return gg; } int gaomaoxian(int x, int y, int state) { memset(vis, 0, sizeof(vis)); memset(dis, 0, sizeof(dis)); vis[x][y][state] = 1; int l = 0, r = 0; int ans = 0; xxx[ans] = x; yyy[ans] = y; st[ans] = state; q[r++] = ans++; while (l<r){ int cur = q[l++]; int xx = xxx[cur]; int yy = yyy[cur]; int state1 = st[cur]; if (xx == 1 && yy == 1) return dis[xx][yy]; for (int i = 0; i < 4; i++){ int x1 = xx + dx[i]; int y1 = yy + dy[i]; if (!gao(state1, xx, yy, x1, y1)) continue; int state2 = gao1(state1, xx, yy, x1, y1); if (vis[x1][y1][state2]) continue; xxx[ans] = x1; yyy[ans] = y1; st[ans] = state2; q[r++] = ans++; vis[x1][y1][state2] = 1; dis[x1][y1] = dis[xx][yy] + 1; } } return -1; } int main() { int x, y, a, b, state, k; int Icase = 0; while (scanf("%d%d%d", &n, &m, &l), n || m || l){ scanf("%d%d", &x, &y); int a1 = x; int b1 = y; state = 0; for (int i = 0; i < l - 1; i++){ scanf("%d%d", &a, &b); int pos = i * 2; if (a - a1 == 1) state |= (1 << pos); if (b - b1 == -1) state |= (1 << (pos + 1)); if (b - b1 == 1) state |= (1 << pos), state |= (1 << (pos + 1)); a1 = a; b1 = b; } cin >> k; memset(Map, 0, sizeof(Map)); for (int i = 0; i<k; i++){ scanf("%d%d", &a, &b); Map[a][b] = 1; } printf("Case %d: ", ++Icase); printf("%d\n", gaomaoxian(x, y, state)); } return 0; }
标签:style blog color os io for div log sp
原文地址:http://www.cnblogs.com/yigexigua/p/3942376.html