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/*
读懂题意,bfs即可AC。
不过注意“超出空间 Memory Limit Exceeded”,需要记录节点的状态,判重。
bool isUsed[MaxN][MaxN][1010]; // 用于判重
*/
1 #include <iostream> 2 #include <cstdlib> 3 #include <cstdio> 4 #include <cstddef> 5 #include <iterator> 6 #include <algorithm> 7 #include <string> 8 #include <locale> 9 #include <cmath> 10 #include <vector> 11 #include <cstring> 12 #include <map> 13 #include <queue> 14 #include <stack> 15 #include <set> 16 using namespace std; 17 const int INF = -0x3f3f3f3f; 18 const int MaxN = 55; 19 const int modPrime = 3046721; 20 21 int step[4][2] = { {-1, 0}, {1, 0}, {0, -1}, {0, 1} }; 22 // 北 南 西 东 23 int R, C; 24 int N; 25 struct Node 26 { 27 int x; 28 int y; 29 int stepCnt; 30 }; 31 32 Node startOff; 33 char imap[MaxN][MaxN]; 34 string direction[1010]; 35 bool isUsed[MaxN][MaxN][1010]; 36 37 int getDirection(string str) 38 { 39 if (str == "NORTH") return 0; 40 if (str == "SOUTH") return 1; 41 if (str == "WEST") return 2; 42 if (str == "EAST") return 3; 43 return -1; 44 } 45 46 void outPut() 47 { 48 for (int i = 0; i < R; ++i) 49 { 50 for (int j = 0; j < C; ++j) 51 { 52 cout << imap[i][j]; 53 } 54 cout << endl; 55 } 56 } 57 58 void Solve() 59 { 60 queue<Node> queNode; 61 queNode.push(startOff); 62 while (!queNode.empty()) 63 { 64 Node node = queNode.front(); 65 queNode.pop(); 66 if (node.stepCnt == (N - 1)) 67 { 68 imap[node.x][node.y] = ‘*‘; 69 continue; 70 } 71 int num = getDirection(direction[node.stepCnt+1]); 72 int x = node.x + step[num][0]; 73 int y = node.y + step[num][1]; 74 while ((x >= 0) && (x < R) && (y >= 0) && (y < C) && (imap[x][y] != ‘X‘)) 75 { 76 Node nodeTmp; 77 nodeTmp.x = x; 78 nodeTmp.y = y; 79 nodeTmp.stepCnt = node.stepCnt + 1; 80 if (!isUsed[nodeTmp.x][nodeTmp.y][nodeTmp.stepCnt]) 81 { 82 queNode.push(nodeTmp); 83 isUsed[nodeTmp.x][nodeTmp.y][nodeTmp.stepCnt] = true; 84 } 85 x = x + step[num][0]; 86 y = y + step[num][1]; 87 } 88 } 89 90 outPut(); 91 } 92 93 94 int main() 95 { 96 #ifdef HOME 97 freopen("in", "r", stdin); 98 //freopen("out", "w", stdout); 99 #endif 100 101 memset(isUsed, false, sizeof(isUsed)); 102 cin >> R >> C; 103 bool getGoal = false; 104 for (int i = 0; i < R; ++i) 105 { 106 cin >> imap[i]; 107 if (!getGoal) 108 { 109 for (int j = 0; j < C; ++j) 110 { 111 if (imap[i][j] == ‘*‘) 112 { 113 imap[i][j] = ‘.‘; 114 startOff.x = i; 115 startOff.y = j; 116 startOff.stepCnt = -1; 117 getGoal = true; 118 break; 119 } 120 } 121 } 122 } 123 cin >> N; 124 for (int i = 0; i < N; ++i) 125 { 126 cin >> direction[i]; 127 } 128 Solve(); 129 130 131 #ifdef HOME 132 cerr << "Time elapsed: " << clock() / CLOCKS_PER_SEC << " ms" << endl; 133 _CrtDumpMemoryLeaks(); 134 #endif 135 return 0; 136 }
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原文地址:http://www.cnblogs.com/shijianming/p/5008920.html