\u975e\u7279\u6b8a\u60c5\u51b5\u4e0d\u63a8\u8350\u4f7f\u7528\u4e07\u80fd\u5934\uff0c\u4f1a\u62d6\u6162\u6574\u4f53\u7684\u7f16\u8bd1\u901f\u5ea6\u3002<\/span><\/p>\n#include <iostream>\r\n#include <vector>\r\n#include <algorithm>\r\n#include <queue>\r\n#include <deque>\r\n#include <unordered_map>\r\n#include <map>\r\n#include <cstring>\r\n#include <cmath>\r\n#include <unordered_set>\r\n#include <set>\r\n#include <utility>\r\n#include <climits>\r\n#include <iomanip>\r\n#include <stack>\r\n#include <bitset>\r\n\r\n#define int long long\r\n#define PII pair<int, int> \r\n#define TLLL tuple<int , int , int>\r\n#define INF 0x3f3f3f3f3f3f3f3f\r\n#define all(v) v.begin() + 1 , v.end()\r\n#define ALL(v) v.begin() , v.end()\r\n#define endl \"\\n\"\r\nusing namespace std;\r\n\r\nconst int N = 1e3 + 10;\r\nint n , m;\r\nint g[N][N] , dist[N][N];\r\nbool st[N][N];\r\n\r\nint dx[] = {0 , 1 , 0 , -1} , dy[] = {1 , 0 , -1 , 0}; \/\/\u56db\u4e2a\u65b9\u5411\r\n\r\nvoid bfs(int sx , int sy)\r\n{\r\n queue<PII> q;\r\n q.push({sx , sy});\r\n st[sx][sy] = true;\r\n\r\n while (q.size())\r\n {\r\n auto t = q.front();\r\n q.pop();\r\n\r\n int x = t.first , y = t.second;\r\n\r\n for (int i = 0 ; i < 4 ; i ++ )\r\n {\r\n int xx = dx[i] + x , yy = dy[i] + y;\r\n\r\n if (xx < 1 || xx > n || yy < 1 || yy > m || g[xx][yy]) continue;\r\n if (st[xx][yy]) continue;\r\n\r\n st[xx][yy] = true;\r\n dist[xx][yy] = dist[x][y] + 1;\r\n q.push({xx , yy});\r\n \r\n if (xx == n && yy == m) return ;\r\n }\r\n }\r\n}\r\n\r\nvoid solve() \r\n{ \r\n cin >> n >> m;\r\n for (int i = 1 ; i <= n ; i ++ ) \r\n for (int j = 1 ; j <= m ; j ++ )\r\n cin >> g[i][j];\r\n \r\n bfs(1 , 1);\r\n\r\n cout << dist[n][m] << endl;\r\n\r\n return ;\r\n}\r\n\r\nsigned main() \r\n{\r\n ios::sync_with_stdio(false);\r\n cin.tie(nullptr), cout.tie(nullptr);\r\n int T = 1;\r\n while (T -- ) solve();\r\n return 0;\r\n}\r\n<\/pre>\n <\/p>\n
\u989d\u5916\u7684\uff0c\u53ef\u4ee5\u4f7f\u7528dijkstra(\u65e0\u8d1f\u6743\u8fb9\u7684\u60c5\u51b5\u4e0b)\u00a0 \u00a0\u5bf9\uff01\u6ca1\u9519\uff0c\u5c31\u662f\u79bb\u6563\u6570\u5b66\u91cc\u4f60\u5b66\u8fc7\u7684\u4e1c\u897f\uff01<\/span><\/del><\/strong><\/p>\n\n- \u89e3\u91ca\uff1a\n
Dijkstra\u7b97\u6cd5\u662f\u4e00\u79cd\u975e\u5e38\u8457\u540d\u4e14\u9ad8\u6548\u7684\u7b97\u6cd5\uff0c\u7528\u4e8e\u5728\u5e26\u6743\u56fe<\/strong>\u4e2d\u5bfb\u627e\u4ece\u4e00\u4e2a\u8d77\u59cb\u70b9\u5230\u6240\u6709\u5176\u4ed6\u70b9\u7684\u6700\u77ed\u8def\u5f84<\/strong>\u3002\u8fd9\u91cc\u7684\u201c\u6743\u201d\u901a\u5e38\u4ee3\u8868\u4e86\u8ddd\u79bb\u3001\u6210\u672c\u3001\u65f6\u95f4\u7b49\u53ef\u91cf\u5316\u7684\u5ea6\u91cf\u3002<\/p>\n\u5b83\u4e0eBFS\u7684\u6838\u5fc3\u533a\u522b\u5728\u4e8e\u201c\u6743\u201d<\/strong>\u3002BFS\u8ba4\u4e3a\u6bcf\u8d70\u4e00\u6b65\u7684\u6210\u672c\u90fd\u662f\u76f8\u540c\u7684\uff08\u53ef\u4ee5\u770b\u4f5c\u6743\u503c\u4e3a1\uff09\uff0c\u5b83\u901a\u8fc7\u201c\u5c42\u6570\u201d\u6765\u8ba1\u7b97\u6700\u77ed\u8ddd\u79bb\u3002\u800cDijkstra\u7b97\u6cd5\u5904\u7406\u7684\u662f\u6743\u503c\u5404\u4e0d\u76f8\u540c\u7684\u56fe<\/strong>\uff0c\u67d0\u4e9b\u8def\u5f84\u53ef\u80fd\u8fb9\u6570\u591a\u4f46\u603b\u6210\u672c\u4f4e\uff0c\u67d0\u4e9b\u53ef\u80fd\u8fb9\u6570\u5c11\u4f46\u603b\u6210\u672c\u9ad8\u3002<\/p>\n\u5b83\u7684\u6838\u5fc3\u601d\u60f3\u53ef\u4ee5\u7528\u4e00\u4e2a\u6bd4\u55bb\u6765\u7406\u89e3\uff1a<\/strong><\/p>\n\u60f3\u8c61\u4f60\u662f\u4e00\u4f4d\u57ce\u5e02\u4ea4\u901a\u6307\u6325\u5b98\uff0c\u76ee\u6807\u662f\u8ba1\u7b97\u4ece\u5e02\u4e2d\u5fc3\uff08\u8d77\u59cb\u70b9\uff09\u5230\u57ce\u5e02\u4e2d\u6240\u6709\u5176\u4ed6\u5730\u70b9\u7684\u6700\u77ed\u884c\u8f66\u65f6\u95f4\u3002<\/p>\n
\n- \n
\u521d\u59cb\u5316<\/strong>\uff1a\u4f60\u9996\u5148\u6807\u8bb0\u5e02\u4e2d\u5fc3\u7684\u65f6\u95f4\u4e3a0\uff0c\u800c\u6240\u6709\u5176\u4ed6\u5730\u70b9\u7684\u65f6\u95f4\u6682\u65f6\u6807\u8bb0\u4e3a\u201c\u65e0\u7a77\u5927\u201d\uff0c\u8868\u793a\u4f60\u8fd8\u4e0d\u77e5\u9053\u5982\u4f55\u5230\u8fbe\u90a3\u91cc\u3002<\/p>\n<\/li>\n- \n
\u8d2a\u5fc3\u9009\u62e9<\/strong>\uff1a\u4f60\u4ece\u5f53\u524d\u5df2\u77e5\u53ef\u8fbe\u7684\u3001\u4e14\u5c1a\u672a\u88ab\u6700\u7ec8\u786e\u8ba4\u7684\u5730\u70b9\u4e2d\uff0c\u9009\u51fa\u79bb\u5e02\u4e2d\u5fc3\u6700\u8fd1\u7684\u90a3\u4e2a<\/strong>\uff08\u4e5f\u5c31\u662f\u5f53\u524d\u8017\u65f6\u6700\u77ed\u7684\u5730\u70b9\uff09\u3002\u4f60\u786e\u4fe1\uff0c\u5bf9\u4e8e\u8fd9\u4e2a\u5730\u70b9\uff0c\u4f60\u5df2\u7ecf\u627e\u5230\u4e86\u7edd\u5bf9\u6700\u77ed\u7684\u8def\u5f84\u3002\u56e0\u4e3a\u5982\u679c\u5b58\u5728\u4e00\u6761\u66f4\u77ed\u7684\u8def\u5f84\uff0c\u90a3\u5b83\u5fc5\u7136\u8981\u7ecf\u8fc7\u4e00\u4e2a\u8017\u65f6\u66f4\u957f\u7684\u5176\u4ed6\u5730\u70b9\uff0c\u8fd9\u663e\u7136\u662f\u4e0d\u53ef\u80fd\u7684\uff08\u524d\u63d0\u662f\u6240\u6709\u6743\u91cd\u4e0d\u80fd\u4e3a\u8d1f\u6570\uff09\u3002<\/p>\n<\/li>\n- \n
\u6269\u6563\u66f4\u65b0<\/strong>\uff1a\u57fa\u4e8e\u8fd9\u4e2a\u521a\u88ab\u786e\u8ba4\u7684\u5730\u70b9\uff0c\u4f60\u53bb\u67e5\u770b\u4ece\u5b83\u51fa\u53d1\u7684\u6240\u6709\u9053\u8def\u3002\u4f60\u8ba1\u7b97\uff1a\u201c\u4ece\u5e02\u4e2d\u5fc3\u5230\u8fd9\u91cc\u7684\u65f6\u95f4\u201d + \u201c\u4ece\u8fd9\u91cc\u5230\u4e0b\u4e00\u4e2a\u8def\u53e3\u7684\u65f6\u95f4\u201d\u3002\u5982\u679c\u8fd9\u4e2a\u603b\u65f6\u95f4\u6bd4\u4e4b\u524d\u8bb0\u5f55\u7684\u5230\u8fbe\u90a3\u4e2a\u8def\u53e3\u7684\u65f6\u95f4\u66f4\u77ed\uff0c\u4f60\u5c31\u66f4\u65b0\u90a3\u4e2a\u8def\u53e3\u7684\u8bb0\u5f55\u3002<\/p>\n<\/li>\n- \n
\u91cd\u590d<\/strong>\uff1a\u4f60\u4e0d\u65ad\u5730\u91cd\u590d\u7b2c2\u548c\u7b2c3\u6b65\uff1a\u4ece\u6240\u6709\u5df2\u77e5\u4f46\u672a\u786e\u8ba4\u7684\u5730\u70b9\u4e2d\u9009\u51fa\u8017\u65f6\u6700\u77ed\u7684\uff0c\u786e\u8ba4\u5b83\uff0c\u7136\u540e\u66f4\u65b0\u5b83\u7684\u90bb\u5c45\u3002\u76f4\u5230\u6240\u6709\u5730\u70b9\u90fd\u88ab\u786e\u8ba4\uff0c\u6216\u8005\u4f60\u627e\u5230\u4e86\u5230\u76ee\u6807\u5730\u70b9\u7684\u6700\u77ed\u8def\u5f84\u3002<\/p>\n<\/li>\n<\/ol>\n<\/li>\n<\/ul>\n\u53c2\u8003\u4ee3\u7801(dijkstra)\uff1a<\/h4>\n
<\/p>\n
#include <iostream>\r\n#include <vector>\r\n#include <algorithm>\r\n#include <queue>\r\n#include <deque>\r\n#include <unordered_map>\r\n#include <map>\r\n#include <cstring>\r\n#include <cmath>\r\n#include <unordered_set>\r\n#include <set>\r\n#include <utility>\r\n#include <climits>\r\n#include <iomanip>\r\n#include <stack>\r\n#include <bitset>\r\n\r\n#define int long long\r\n#define PII pair<int, int> \r\n#define TLLL tuple<int , int , int>\r\n#define INF 0x3f3f3f3f3f3f3f3f\r\n#define inf 0x3f\r\n#define all(v) v.begin() + 1 , v.end()\r\n#define ALL(v) v.begin() , v.end()\r\n#define endl \"\\n\"\r\nusing namespace std;\r\n\r\nconst int N = 4e6 + 10;\r\nint e[N] , ne[N] , h[N] , idx , dist[N];\r\nbool st[N];\r\n\r\n\/\/\u94fe\u5f0f\u524d\u5411\u661f\u5b58\u56fe\uff0c\u76f8\u5173\u6982\u5ff5\u53ef\u4ee5\u53c2\u8003\u8fc7\u5f80\u6587\u7ae0->\u56fe\u8bba\u57fa\u7840-\u900f\u6790\u94fe\u5f0f\u524d\u5411\u661f\r\ninline void add(int a , int b)\r\n{\r\n e[idx] = b , ne[idx] = h[a] , h[a] = idx ++;\r\n}\r\n\r\n\/\/\u5c06\u4e8c\u7ef4\u5750\u6807\u8f6c\u5316\u4e3a\u4e00\u7ef4\uff08\u5373\uff1a\u4ece\u4e0a\u5230\u4e0b\uff0c\u4ece\u5de6\u5230\u53f3\uff0c\u4f9d\u6b21\u7f16\u53f7\u4e3a1,2,3,...,n * m\uff09\u3002\r\ninline int transIndex(int a , int b , int m)\r\n{\r\n return (a - 1) * m + b;\r\n}\r\n\r\n\/\/dijkstra\r\nvoid dijkstra()\r\n{\r\n memset(st , false , sizeof st);\r\n memset(dist , inf , sizeof dist);\r\n\r\n priority_queue<PII , vector<PII> , greater<PII> > heap;\r\n heap.push({0 , 1});\r\n\r\n dist[1] = 0;\r\n st[1] = true;\r\n\r\n while (heap.size())\r\n {\r\n auto t = heap.top();\r\n heap.pop();\r\n\r\n int distance = t.first , index = t.second;\r\n\r\n for (int i = h[index] ; ~i ; i = ne[i])\r\n {\r\n int j = e[i];\r\n\r\n if (dist[j] > distance + 1)\r\n {\r\n dist[j] = distance + 1;\r\n heap.push({ dist[j] , j});\r\n }\r\n }\r\n }\r\n\r\n return ;\r\n}\r\n\r\n\/\/\u51fd\u6570\u672c\u4f53\r\nvoid solve()\r\n{\r\n int n , m;\r\n cin >> n >> m;\r\n vector<vector<int> > g(n + 1 , vector<int>(m + 1));\r\n for (int i = 1 ; i <= n ; i ++ )\r\n for (int j = 1 ; j <= m ; j ++ )\r\n cin >> g[i][j];\r\n \r\n memset(h , -1 , sizeof h);\r\n int dx[] = {0 , 1 , 0 , -1} , dy[] = {1 , 0 , -1 , 0}; \/\/\u56db\u4e2a\u65b9\u5411\r\n\r\n\/\/\u5750\u6807\u8f6c\u6362\r\n for (int i = 1 ; i <= n ; i ++ )\r\n {\r\n for (int j = 1 ; j <= m ; j ++ )\r\n {\r\n if (g[i][j]) continue;\r\n\r\n int u = transIndex(i , j , m);\r\n\r\n for (int k = 0 ; k < 4 ; k ++ )\r\n {\r\n int x = i + dx[k] , y = j + dy[k];\r\n\r\n if (x < 1 || x > n || y < 1 || y > m || g[x][y]) continue;\r\n \r\n int v = transIndex(x , y , m);\r\n add(u , v) , add(v , u); \/\/\u9898\u76ee\u63cf\u8ff0\u53ef\u4ee5\u4e0a\u4e0b\u5de6\u53f3\uff0c\u5373 \u53cc\u5411\u56fe\r\n }\r\n }\r\n }\r\n\r\n dijkstra();\r\n int end = transIndex(n , m , m);\r\n\r\n cout << dist[end] << endl;\r\n\r\n return ;\r\n}\r\n\r\nsigned main() \r\n{\r\n ios::sync_with_stdio(false);\r\n cin.tie(nullptr), cout.tie(nullptr);\r\n int T = 1;\r\n \/\/ cin >> T;\r\n while (T -- ) solve();\r\n return 0;\r\n}\r\n<\/pre>\n <\/p>\n
\u6301\u7eed\u66f4\u65b0\u4e2d...<\/p>\n
<\/p>\n","protected":false},"excerpt":{"rendered":"
\u9762\u5bf9\u65b0\u624b\u5411\u7684\u66b4\u529b\u8fc7\u9898\u6280\u5de7-cpp njtc-\u7b97\u7ade\u961f-yxy \u5199\u5728\u524d\u9762 \u5728\u4e00\u4e9b\u7c7b\u4f3c\u4e8e\u8ff7\u5bab\u95ee\u9898\u3001\u8d70\u683c\u5b50\u3001\u6700\u77ed\u8def\u3001\u6700\u957f\u8def\u3001\u5bfb\u8def\u95ee\u9898\u3001\u6811\u4e0a …<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"emotion":"","emotion_color":"","title_style":"","license":"","footnotes":""},"categories":[7],"tags":[12,17,16,15,13,14],"class_list":["post-411","post","type-post","status-publish","format-standard","hentry","category-algorithm","tag-algorithm","tag-bfs","tag-dfs","tag-dijkstra","tag-13","tag-14"],"_links":{"self":[{"href":"https:\/\/m.qzcy2.top\/index.php\/wp-json\/wp\/v2\/posts\/411","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/m.qzcy2.top\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/m.qzcy2.top\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/m.qzcy2.top\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/m.qzcy2.top\/index.php\/wp-json\/wp\/v2\/comments?post=411"}],"version-history":[{"count":11,"href":"https:\/\/m.qzcy2.top\/index.php\/wp-json\/wp\/v2\/posts\/411\/revisions"}],"predecessor-version":[{"id":423,"href":"https:\/\/m.qzcy2.top\/index.php\/wp-json\/wp\/v2\/posts\/411\/revisions\/423"}],"wp:attachment":[{"href":"https:\/\/m.qzcy2.top\/index.php\/wp-json\/wp\/v2\/media?parent=411"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/m.qzcy2.top\/index.php\/wp-json\/wp\/v2\/categories?post=411"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/m.qzcy2.top\/index.php\/wp-json\/wp\/v2\/tags?post=411"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}