标签:for set swap ems end span new eof define
题目链接:https://www.luogu.org/problemnew/show/P2324
不懂怎么剪枝,所以说,,我需要氧气。。
第一道A*
1 // luogu-judger-enable-o2 2 #include <cstdio> 3 #include <iostream> 4 #include <algorithm> 5 #include <cstring> 6 #define maxn 10 7 using namespace std; 8 int T, ans = 16, mx, sx, sy; 9 int aim[6][6] = {{0,0,0,0,0,0}, 10 {0,2,2,2,2,2}, 11 {0,1,2,2,2,2}, 12 {0,1,1,0,2,2}, 13 {0,1,1,1,1,2}, 14 {0,1,1,1,1,1}}; 15 int dx[8] = {-2,-1,1,2,2,1,-1,-2}; 16 int dy[8] = {1,2,2,1,-1,-2,-2,-1}; 17 int a[maxn][maxn]; 18 inline int h() 19 { 20 int ret = 0; 21 for(int i = 1; i <= 5; i++) 22 for(int j = 1; j <= 5; j++) 23 if(a[i][j] != aim[i][j]) ret++; 24 return ret; 25 } 26 inline bool move(int x, int y) 27 { 28 if(x >= 1 && x <= 5 && y >= 1 && y <= 5) return true; 29 return false; 30 } 31 void A_star(int now, int x, int y) 32 { 33 if(now > mx) return; 34 int cnt = h(); 35 if(cnt == 0) 36 { 37 ans = min(ans, now); 38 return; 39 } 40 if(cnt + now - 1 > mx) return; 41 int nowx, nowy; 42 for(int i = 0; i <= 7; i++) 43 { 44 nowx = x + dx[i]; 45 nowy = y + dy[i]; 46 if(move(nowx, nowy)) 47 { 48 swap(a[nowx][nowy],a[x][y]); 49 A_star(now+1,nowx,nowy); 50 swap(a[nowx][nowy],a[x][y]); 51 } 52 } 53 } 54 int main() 55 { 56 cin.sync_with_stdio(false); 57 cin>>T; 58 while(T--) 59 { 60 char s; 61 ans = 16; 62 memset(a,0,sizeof(a)); 63 for(int i = 1; i <= 5; i++) 64 for(int j = 1; j <= 5; j++) 65 { 66 cin>>s; 67 if(s != ‘*‘) 68 a[i][j] = s + 1 - ‘0‘; 69 if(s == ‘*‘) 70 { 71 a[i][j] = 0; 72 sx = i; 73 sy = j; 74 } 75 } 76 for(mx = 1; mx <= 15; mx++) 77 { 78 A_star(0,sx,sy); 79 if(ans == mx) break; 80 81 } 82 if(ans == 16) 83 { 84 cout<<-1<<endl; 85 } 86 else 87 { 88 cout<<ans<<endl; 89 } 90 } 91 return 0; 92 }
【luogu P2324 [SCOI2005]骑士精神】 题解
标签:for set swap ems end span new eof define
原文地址:https://www.cnblogs.com/MisakaAzusa/p/9004653.html