poj1726
黑书上的题目的加强版
思路差不多。。这届看黑书p117例题4 ”舞蹈家“怀特先生
1 /* 2 State:Accepted 3 Time:2013-03-10 02:44:14 4 */ 5 #include <iostream> 6 #include <cstring> 7 #include <string> 8 #include <cstdlib> 9 #include <cstdio> 10 #include <algorithm> 11 #include <cmath> 12 const int num[4][4]= 13 {{3,5,5,7}, 14 {5,3,7,5}, 15 {5,7,3,5}, 16 {7,5,5,3}}; 17 using namespace std; 18 int f[150][6][6][5] , lx[150][6][6][5] , ly[150][6][6][5], 19 lz[150][6][6][5] , a[110]; 20 int n ,ans ,ansx, ansy, ansz; 21 char s[105]; 22 const char path[3]={'.','L','R'}; 23 24 bool left(int x, int y){ return (x == 1 || x == 2) && y == 0; } 25 bool right(int x , int y){ return (y == 1 || y == 2) && x == 3;} 26 27 void updata(int i , int x , int y , int now){ 28 if (x == now || (!left(x ,y))){ 29 if (f[i+1][now][y][1] > f[i][x][y][0] + 1){ 30 f[i+1][now][y][1] = f[i][x][y][0] + 1; 31 lx[i+1][now][y][1] = x; 32 ly[i+1][now][y][1] = y; 33 lz[i+1][now][y][1] = 0; 34 } 35 if (f[i+1][now][y][1] > f[i][x][y][2] + 1){ 36 f[i+1][now][y][1] = f[i][x][y][2] + 1; 37 lx[i+1][now][y][1] = x; 38 ly[i+1][now][y][1] = y; 39 lz[i+1][now][y][1] = 2; 40 } 41 if (f[i+1][now][y][1] > f[i][x][y][1] + num[x][now]){ 42 f[i+1][now][y][1] = f[i][x][y][1] + num[x][now]; 43 lx[i+1][now][y][1] = x; 44 ly[i+1][now][y][1] = y; 45 lz[i+1][now][y][1] = 1; 46 } 47 } 48 if (y == now || (!right(x ,y))){ 49 if (f[i+1][x][now][2] > f[i][x][y][0] + 1){ 50 f[i+1][x][now][2] = f[i][x][y][0] + 1; 51 lx[i+1][x][now][2] = x; 52 ly[i+1][x][now][2] = y; 53 lz[i+1][x][now][2] = 0; 54 } 55 if (f[i+1][x][now][2] > f[i][x][y][1] + 1){ 56 f[i+1][x][now][2] = f[i][x][y][1] + 1; 57 lx[i+1][x][now][2] = x; 58 ly[i+1][x][now][2] = y; 59 lz[i+1][x][now][2] = 1; 60 } 61 if (f[i+1][x][now][2] > f[i][x][y][2] + num[y][now]){ 62 f[i+1][x][now][2] = f[i][x][y][2] + num[y][now]; 63 lx[i+1][x][now][2] = x; 64 ly[i+1][x][now][2] = y; 65 lz[i+1][x][now][2] = 2; 66 } 67 } 68 69 } 70 71 void print(int i , int j, int k , int l){ 72 if (i == 0) return; 73 int x = lx[i][j][k][l]; 74 int y = ly[i][j][k][l]; 75 int z = lz[i][j][k][l]; 76 print(i - 1, x,y,z); 77 printf("%c",path[l]); 78 } 79 80 void solve(){ 81 n = strlen(s); 82 for (int i = 0; i < n; ++i){ 83 if (s[i] == '.' ) a[i + 1] = 4; 84 if (s[i] == 'L' ) a[i + 1] = 0; 85 if (s[i] == 'U' ) a[i + 1] = 1; 86 if (s[i] == 'D' ) a[i + 1] = 2; 87 if (s[i] == 'R' ) a[i + 1] = 3; 88 } 89 for (int i = 0; i <= n ; ++i) 90 for (int j = 0; j <= 4; ++j) 91 for (int k = 0; k <= 4; ++k) 92 for (int l = 0; l <= 2; ++l) 93 f[i][j][k][l] = 100000000; 94 95 f[0][0][3][0] = 0; 96 for (int i = 0; i < n ; ++i) 97 for (int j = 0; j < 4; ++j) 98 for (int k = 0; k < 4; ++k) 99 if (j != k) 100 if (a[i + 1] != 4) updata(i , j, k , a[i+1]); 101 else { 102 for (int l = 0 ; l < 4; ++l) updata(i , j , k , l); 103 for (int l = 0; l <= 2; ++l) 104 if (f[i+1][j][k][0] > f[i][j][k][l]){ 105 f[i+1][j][k][0] = f[i][j][k][l]; 106 lx[i+1][j][k][0] = j; 107 ly[i+1][j][k][0] = k; 108 lz[i+1][j][k][0] = l; 109 } 110 } 111 ans = 100000000; 112 for (int i = 0; i < 4; ++i) 113 for (int j = 0; j < 4; ++j) 114 for (int k = 0; k < 3; ++k) 115 if (i != j && f[n][i][j][k] < ans){ 116 ans = f[n][i][j][k]; 117 ansx = i; 118 ansy = j; 119 ansz = k; 120 } 121 print(n, ansx ,ansy,ansz); 122 printf("\n"); 123 124 125 } 126 127 int main(){ 128 freopen("poj1726.in","r", stdin); 129 freopen("poj1726.out","w",stdout); 130 scanf("%s",&s); 131 while (s[0] !='#'){ 132 solve(); 133 scanf("%s",&s); 134 } 135 136 }
