{"id":132,"date":"2010-08-07T08:38:28","date_gmt":"2010-08-07T00:38:28","guid":{"rendered":"http:\/\/www.shuizilong.com\/house\/?p=132"},"modified":"2012-12-20T06:47:29","modified_gmt":"2012-12-19T22:47:29","slug":"%e4%b8%8d%e7%bb%b4%e6%8a%a4pos%e6%95%b0%e7%bb%84%e7%9a%84%e6%83%85%e5%86%b5%e4%b8%8b%e4%bc%98%e7%be%8e%e7%9a%84%e5%86%99%e5%87%ba-stldijkstra","status":"publish","type":"post","link":"https:\/\/www.shuizilong.com\/house\/archives\/%e4%b8%8d%e7%bb%b4%e6%8a%a4pos%e6%95%b0%e7%bb%84%e7%9a%84%e6%83%85%e5%86%b5%e4%b8%8b%e4%bc%98%e7%be%8e%e7%9a%84%e5%86%99%e5%87%ba-stldijkstra\/","title":{"rendered":"\u4e0d\u7ef4\u62a4pos\u6570\u7ec4\u7684\u60c5\u51b5\u4e0b\u4f18\u7f8e\u7684\u5199\u51fa STL:Dijkstra \u2026"},"content":{"rendered":"

Background :<\/h3>\n

\u6211\u5148\u63cf\u8ff0\u4e00\u4e0b\u8fd9\u4e2a\u95ee\u9898\u5427\uff08\u5c31\u5728\u4e4b\u524d\u7684\u661f\u671f\u8fd8\u548c doc \u8ba8\u8bba\u8fc7\u5462\uff09\uff0c\u5c31\u662f\u5982\u4f55\u7528STL\u4f18\u7f8e\u7684\u5199\u51fa\u52a0\u5806\u4f18\u5316\u7684 dijktra … \u9047\u5230\u7684\u56f0\u96be\u4e3b\u8981\u662f\u65e0\u6cd5\u5f97\u5230\u7ed3\u70b9\u5728\u5806\u4e2d\u7684\u4f4d\u7f6e…. \uff08\u9664\u975e\u53ef\u4ee5\u6709\u529e\u6cd5\u5199\u5230 STL \u91cc\u9762\u53bb\u3002\u3002\u591a\u52a0\u4e00\u70b9\u4e1c\u897f\uff0c\u4f46\u8fd9\u4ea6\u662f\u4e00\u4ef6\u56f0\u96be\u4e4b\u4e8b\u5440\u3002\uff0c\u6211\u4eec\u7684\u60f3\u6cd5\u662f\u5982\u679c\u8981\u9047\u5230\u8fd9\u79cd\u60c5\u51b5\u65f6\u5fc5\u987b\u624b\u5199\u5806\u3002\uff08\u6216\u8005\u6211\u4eec\u5199\u4e00\u4e9b Spfa \u66ff\u4ee3\u4e00\u4e0b\u4e5f\u4e0d\u9519\u3002\uff09<\/p>\n

\u52a0\u5806\u7684Dijkstra \u662f\u6211\u9ad8\u4e8c\u6691\u5047\u7684\u65f6\u5019\u81ea\u5df1\u7814\u7a76\u51fa\u6765\u7684\uff08\u8fd9\u82b1\u4e86\u6211\u5f88\u4e45\u7684\u4e00\u6bb5\u65f6\u95f4\uff09\uff0c\u6240\u4ee5\u5370\u8c61\u5f88\u6df1\uff0c\u800c\u4e14\u6211\u4e5f\u60f3\u501f\u6b64\u673a\u4f1a\u6bd4\u8f83\u4e00\u4e0b\u4e0d\u540c\u7684\u5199\u6cd5\u3002<\/p>\n

\u4eca\u5929\u4e0a\u5348\u5199 Astar \u7684\u65f6\u5019<\/a> \uff0c\u6211\u627e\u5230\u4e86\u89e3\u51b3\u8fd9\u4e2a\u95ee\u9898\u7684\u4e00\u79cd\u65b9\u6cd5\u3002\uff08( \u2299 o \u2299 )o… \uff03\u2014\uff0a@\u2014\uff08\uff0a\uff09
\n…
\n<\/p>\n

Archieve :<\/h3>\n

Problem: Rqnoj 341 \u661f\u95e8\u8df3\u8dc3<\/a><\/p>\n

\r\n#include <iostream>\r\n#include <vector>\r\nusing namespace std;\r\nconst int INF = 100000;\r\nconst int N = 30001;\r\nstruct edge{\r\n    int p, w;\r\n};\r\n\r\nvector<edge> adj[N];\r\nint Q[N], H[N], P[N]; int size;\r\nint n, m;\r\n\r\nvoid exchange(int a, int b){\r\n    swap(Q[a], Q[b]); swap(H[a], H[b]);\r\n    P[H[a]] = a; P[H[b]] = b;\r\n}\r\n\r\nvoid down(int x){\r\n    int l, r, k;\r\n    while (true){\r\n        l = x << 1; r = l + 1;\r\n        if (l<=size&&Q[l]<Q[x]) k = l; else k = x;\r\n        if (r<=size&&Q[r]<Q[k]) k = r;\r\n        if (x==k) return;\r\n        exchange(x, k);\r\n        x = k;\r\n    }\r\n}\r\n\r\nvoid up(int x){\r\n    int y = x >> 1;\r\n    while (y>0&&Q[x]<Q[y]){\r\n        exchange(x, y);\r\n        x = y; y >>= 1;\r\n    }\r\n}\r\n\r\nint extract(){\r\n    exchange(1, size--); down(1);\r\n    return(H[size+1]);\r\n}\r\n\r\nvoid decrease(int x, int k){\r\n    Q[x] = k; up(x);\r\n}\r\n\r\n\r\n\r\nvoid init(){\r\n    cin >> n >> m;\r\n\r\n    int a, b; edge x;\r\n    for (int i=0;i<m;i++){\r\n        cin >> a >> b >> x.w;\r\n        x.p = b; adj[a].push_back(x);\r\n        x.p = a; adj[b].push_back(x);\r\n    }\r\n}\r\nvoid dijkstra(){\r\n    for (int i=1;i<=n;i++){\r\n        P[i] = H[i] = i;\r\n        Q[i] = INF;\r\n    }\r\n    size = n, Q[1] = 0;\r\n\r\n    int u, v;\r\n    for (int i=0;i<n;i++){\r\n        u = extract();        \r\n        if (u == n) return;\r\n        for (vector<edge>::iterator it=adj[u].begin();it!=adj[u].end();it++){\r\n            v = (*it).p;\r\n            if (P[v]<=size&&Q[P[u]] + (*it).w < Q[P[v]]) \r\n                decrease(P[v], Q[P[u]] + (*it).w);                \r\n        }\r\n    }\r\n}\r\nint main(){\r\n    init(); dijkstra();\r\n    cout << Q[P[n]] << endl;\r\n}\r\n<\/pre>\n
\r\n#include <iostream>\r\n#include <vector>\r\nusing namespace std;\r\nconst int INF = 100000;\r\nconst int N = 30001;\r\nstruct edge{\r\n    int p, w;\r\n};\r\n\r\nvector<edge> adj[N];\r\nint Q[N], D[N], P[N];\r\nint size;\r\nint n, m;\r\n\r\nvoid exchange(int a, int b){\r\n    swap(Q[a], Q[b]);\r\n    P[Q[a]] = a; P[Q[b]] = b;\r\n}\r\n\r\nvoid down(int x){\r\n    int l, r, k;\r\n    while (true){\r\n        l = x << 1; r = l + 1;\r\n        if (l<=size&&D[Q[l]]<D[Q[x]]) k = l; else k = x;\r\n        if (r<=size&&D[Q[r]]<D[Q[k]]) k = r;\r\n        if (x==k) return;\r\n        exchange(x, k);\r\n        x = k;\r\n    }\r\n}\r\n\r\nvoid up(int x){\r\n    int y = x >> 1;\r\n    while (y>0&&D[Q[x]]<D[Q[y]]){\r\n        exchange(x, y);\r\n        x = y; y >>= 1;\r\n    }\r\n}\r\n\r\nint extract(){\r\n    exchange(1, size--); down(1);\r\n    return(Q[size+1]);\r\n}\r\n\r\nvoid decrease(int x, int k){\r\n    D[x] = k; up(P[x]);\r\n}\r\n\r\n\r\n\r\nvoid init(){\r\n    cin >> n >> m;\r\n\r\n    int a, b; edge x;\r\n    for (int i=0;i<m;i++){\r\n        cin >> a >> b >> x.w;\r\n        x.p = b; adj[a].push_back(x);\r\n        x.p = a; adj[b].push_back(x);\r\n    }\r\n}\r\nvoid dijkstra(){\r\n    for (int i=1;i<=n;i++){\r\n        Q[i] = P[i] = i; D[i] = INF;\r\n    }\r\n    size = n, D[1] = 0;\r\n\r\n    int u, v;\r\n    for (int i=0;i<n;i++){\r\n        u = extract();\r\n        if (u == n) return;\r\n        for (vector<edge>::iterator it=adj[u].begin();it!=adj[u].end();it++){\r\n            v = (*it).p;\r\n            if (P[v]<=size&&D[u] + (*it).w < D[v])\r\n                decrease(v, D[u] + (*it).w);\r\n        }\r\n    }\r\n}\r\nint main(){\r\n    init(); dijkstra();\r\n    cout << D[n] << endl;\r\n}\r\n<\/pre>\n
Handle \u6570\u7ec4 \u8bb0\u5f55\u5806\u4e2d\u7684\u5143\u7d20\u5bf9\u5e94\u54ea\u4e2a\u7ed3\u70b9\u3002
\nPos \u6570\u7ec4 \u7ef4\u62a4\u6bcf\u4e2a\u7ed3\u70b9\u5728\u5806\u4e2d\u7684\u4f4d\u7f6e\u3002
\n\u8fd9\u4e24\u4e2a\u662f\u4e00\u7ec4\u4e92\u9006\u64cd\u4f5c… \u4e5f\u5c31\u662f
\nHandle[Pos[i]] = Pos[Handle[i]] = i;<\/p>\n
Queue \u6570\u7ec4\u8bb0\u5f55\u5806\u4e2d\u5143\u7d20\u7684\u5173\u952e\u5b57\uff0c\u4e5f\u5c31\u662f\u5230\u6e90\u70b9\u7684 Dist\uff0c \u6700\u77ed\u8def\u5f84\u4f30\u8ba1\u3002 <\/p>\n
1.
\n\u4ee3\u7801\u4e00 \u4e2d void exchange() \u7684\u4f4d\u7f6e
\nP[H[a]] = a; P[H[b]] = b;
\n\u662f\u4ece
\nswap(P[H[a]], P[H[b]]);
\n\u6362\u5199\u7684.
\n\u8fd9\u6837\u5199\u53ef\u4ee5\u5c11\u4e00\u4e2a\u8bed\u53e5\u4e0d\u8fc7\u4f1a\u6839\u636eH\u6570\u7ec4\u6709\u6ca1\u6709\u4ea4\u6362\u800c\u6709\u5f71\u54cd\u3002
\n\u6bd4\u5982\u5982\u679c\u653e\u524d\u9762\u7684\u8bdd\u4f1a\u8981\u5199\u6210\u8fd9\u6837\u3002
\nP[H[a]] = b; P[H[b]] = a;<\/p>\n
2.
\n\u7ecf\u8fc7\u89c2\u5bdf\uff0c\u6211\u4eec\u53d1\u73b0 Handle \u5143\u7d20\u548c Key \u5143\u7d20\u540c\u65f6\u5c5e\u4e8e\u5806\u4e2d\u7684\u4e00\u4e2a\u7ed3\u70b9\uff0c\u8fd9\u6837\u53ef\u4ee5\u628a\u4ed6\u4eec\u6253\u5305\u6210\u4e00\u4e2a Struct \uff0c\u4ea4\u6362\u7684\u65f6\u5019\u540c\u65f6\u8fdb\u884c\u3002<\/p>\n
\u4f46\u662f Pos \u6570\u7ec4\u5c31\u4e0d\u884c\u4e86\uff0c\u4e8b\u5b9e\u4e0a\u6211\u4eec\u53d1\u73b0\u95ee\u9898\u5c31\u51fa\u5728 Pos \u6570\u7ec4\u4e0a….
\n\u56e0\u4e3a\u5728\u4f7f\u7528 STL:Priority_queue \u7684\u65f6\u5019\uff0c\u6ca1\u6709\u529e\u6cd5\u5f80\u91cc\u9762\u6539\u5199 void exchange()\uff0c\u4e5f\u5c31\u4e0d\u80fd\u5373\u65f6\u7684\u7ef4\u62a4 Pos \u6570\u7ec4\u4e86\u3002<\/p>\n
\u6211\u4eec\u5e0c\u671b\u53ef\u4ee5\u4ee5\u67d0\u79cd\u65b9\u5f0f\u907f\u514d Pos \u6570\u7ec4\u7684\u51fa\u73b0\uff0c\u56e0\u6b64\u6211\u4eec\u5c1d\u8bd5\u4e86\u4ee3\u7801II\u3002<\/p>\n
3.<\/p>\n
\u4f46\u662f\u6211\u4eec\u5f88\u5feb\u53d1\u73b0\u4ee3\u7801\u4e8c\u53ea\u662f\u5c06\u5173\u952e\u5b57\u4fdd\u5b58\u5728\u4e86\u5806\u5916\u3002\u3002\u5e76\u672a\u80fd\u5b8c\u6210\u4e4b\u524d\u7684\u8981\u6c42\u3002\u3002\u3002\u770b\u8d77\u6765\u95ee\u9898\u53d8\u5f97\u975e\u5e38\u68d8\u624b\uff0c\u56e0\u4e3a\u677e\u5f1b\u64cd\u4f5c\u91cc\u5fc5\u987b\u8981\u7528\u5bf9\u54e6\u554a\uff0c\u4f3c\u4e4e\u6ca1\u6709\u529e\u6cd5\u4e0d\u5199 Pos \u6570\u7ec4\u3002\u3002\u3002<\/p>\n
\u9664\u975e\uff0c
\n1. \u5982\u679c\u9898\u76ee\u4e0d\u5b8c\u5168\u8981\u6c42\u6b7b\u7528\u90bb\u63a5\u8868\u5b58\u50a8\uff0c\u90a3\u6837\u7528\u90bb\u63a5\u77e9\u9635\u505aO(1)\u7684\u6d4b\u8bd5\u7684\u8bdd\uff0c\u53ef\u4ee5\u76f4\u63a5\u626b\u63cf\u5806\u3002\uff08\u56e0\u4e3a\u53ef\u4ee5\u5bb9\u6613\u7684\u5f97\u5230 Handle \u6570\u7ec4\u3002\uff09
\n\u4f46\u662f\u8fd9\u6837\u5c31\u6ca1\u6709\u7528\u4e86\u3002<\/p>\n
2. \u5bf9\u53d6\u51fa\u4e00\u4e2a\uff0c\u677e\u5f1b\u5b8c\u6240\u6709\u7ed3\u70b9\u540e\uff0c\u5728\u4e00\u8d77\u7ef4\u62a4\u5806\u3002\u3002\u3002
\n\uff08\u6211\u8fd8\u4e0d\u80fd\u786e\u5b9a\u8fd9\u4e2a\u65b9\u6cd5\u6709\u591a\u5927\u7684\u53ef\u884c\u3002\u3002\u3002\u4f46\u662f\u611f\u89c9\u548c\u4e0a\u9762\u90a3\u79cd\u4e00\u6837\uff0c\u90fd\u4e0d\u9002\u5408\u5904\u7406\u7a00\u758f\u56fe\uff09<\/p>\n
\u3002
\n\u3002\u3002\u3002
\n\u4f46\u662f\u4e0b\u9762\u786e\u5b9e\u5b58\u5728\u4e00\u79cd\uff0c\u7b80\u6d01\u7684\u65b9\u6cd5\u89e3\u51b3\u8fd9\u4e2a\u95ee\u9898\u3002
\n\u901a\u8fc7\u5141\u8bb8\u5806\u4e2d\u4e00\u4e2a\u70b9\u5b58\u5728\u591a\u6b21\uff0c\u505a\u5ef6\u8fdf\u8ba4\u53ef\u3002\uff08\u989d\uff0c\u7528\u7a7a\u95f4\u6362\u53d6\u7f16\u7a0b\u590d\u6742\u5ea6\u3002\u3002\u3002\uff09<\/p>\n
\r\n#include <iostream>\r\n#include <vector>\r\n#include <queue>\r\nusing namespace std;\r\nconst int INF = 1000000;\r\nconst int N = 30001;\r\nstruct edge{\r\n    int p, w;\r\n};\r\nvector<edge> adj[N];\r\nint D[N]; bool C[N];\r\nint n, m;\r\n\r\n\r\nstruct comp{\r\n    bool operator()(int a, int b){\r\n        return (D[a]>D[b]);\r\n    }\r\n};\r\n\r\npriority_queue< int, vector<int>, comp > Q;\r\n\r\n\r\nvoid init(){\r\n    cin >> n >> m;\r\n\r\n    int a, b; edge x;\r\n    for (int i=0;i<m;i++){\r\n        cin >> a >> b >> x.w;\r\n        x.p = b; adj[a].push_back(x);\r\n        x.p = a; adj[b].push_back(x);\r\n    }\r\n}\r\nvoid dijkstra(){\r\n    for (int i=1;i<=n;i++){\r\n        D[i] = INF; C[i] = true;\r\n    }\r\n    while (!Q.empty()) Q.pop();\r\n    Q.push(1);\r\n    D[1] = 0;\r\n\r\n    int u, v;\r\n    for (int i=0;i<n;i++){\r\n        while (!Q.empty()){\r\n            u = Q.top(), Q.pop();\r\n            if (C[u]) break;\r\n        }\r\n        if (!C[u]||u==n) return;\r\n        C[u] = false;\r\n\r\n        for (vector<edge>::iterator it=adj[u].begin();it!=adj[u].end();it++){\r\n            v = (*it).p;\r\n            if (C[v]&&D[u] + (*it).w < D[v]){\r\n                D[v] = D[u] + (*it).w;\r\n                Q.push(v);\r\n            }\r\n        }\r\n    }\r\n}\r\nint main(){\r\n    init(); dijkstra();\r\n    cout << D[n] << endl;\r\n}\r\n<\/pre>\n","protected":false},"excerpt":{"rendered":"
Background : \u6211\u5148\u63cf\u8ff0\u4e00\u4e0b\u8fd9\u4e2a\u95ee\u9898\u5427\uff08\u5c31\u5728\u4e4b\u524d\u7684\u661f\u671f\u8fd8\u548c doc \u8ba8\u8bba\u8fc7\u5462\uff09\uff0c\u5c31\u662f\u5982\u4f55\u7528STL\u4f18\u7f8e\u7684\u5199\u51fa\u52a0\u5806\u4f18\u5316\u7684 dijktra … \u9047\u5230\u7684\u56f0\u96be\u4e3b\u8981\u662f\u65e0\u6cd5\u5f97\u5230\u7ed3\u70b9\u5728\u5806\u4e2d\u7684\u4f4d\u7f6e…. \uff08\u9664\u975e\u53ef\u4ee5\u6709\u529e\u6cd5\u5199\u5230 STL \u91cc\u9762\u53bb\u3002\u3002\u591a\u52a0\u4e00\u70b9\u4e1c\u897f\uff0c\u4f46\u8fd9\u4ea6\u662f\u4e00\u4ef6\u56f0\u96be\u4e4b\u4e8b\u5440\u3002\uff0c\u6211\u4eec\u7684\u60f3\u6cd5\u662f\u5982\u679c\u8981\u9047\u5230\u8fd9\u79cd\u60c5\u51b5\u65f6\u5fc5\u987b\u624b\u5199\u5806\u3002\uff08\u6216\u8005\u6211\u4eec\u5199\u4e00\u4e9b Spfa \u66ff\u4ee3\u4e00\u4e0b\u4e5f\u4e0d\u9519\u3002\uff09 \u52a0\u5806\u7684Dijkstra \u662f\u6211\u9ad8\u4e8c\u6691\u5047\u7684\u65f6\u5019\u81ea\u5df1\u7814\u7a76\u51fa\u6765\u7684\uff08\u8fd9\u82b1\u4e86\u6211\u5f88\u4e45\u7684\u4e00\u6bb5\u65f6\u95f4\uff09\uff0c\u6240\u4ee5\u5370\u8c61\u5f88\u6df1\uff0c\u800c\u4e14\u6211\u4e5f\u60f3\u501f\u6b64\u673a\u4f1a\u6bd4\u8f83\u4e00\u4e0b\u4e0d\u540c\u7684\u5199\u6cd5\u3002 \u4eca\u5929\u4e0a\u5348\u5199 Astar \u7684\u65f6\u5019 \uff0c\u6211\u627e\u5230\u4e86\u89e3\u51b3\u8fd9\u4e2a\u95ee\u9898\u7684\u4e00\u79cd\u65b9\u6cd5\u3002\uff08( \u2299 o \u2299 )o… \uff03\u2014\uff0a@\u2014\uff08\uff0a\uff09 …<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"jetpack_post_was_ever_published":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":false,"jetpack_social_options":{"image_generator_settings":{"template":"highway","enabled":false}}},"categories":[1],"tags":[100,7],"class_list":["post-132","post","type-post","status-publish","format-standard","hentry","category-uncategorized","tag-100","tag-7"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_shortlink":"https:\/\/wp.me\/p2tdP7-28","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/www.shuizilong.com\/house\/wp-json\/wp\/v2\/posts\/132","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.shuizilong.com\/house\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.shuizilong.com\/house\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.shuizilong.com\/house\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.shuizilong.com\/house\/wp-json\/wp\/v2\/comments?post=132"}],"version-history":[{"count":0,"href":"https:\/\/www.shuizilong.com\/house\/wp-json\/wp\/v2\/posts\/132\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.shuizilong.com\/house\/wp-json\/wp\/v2\/media?parent=132"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.shuizilong.com\/house\/wp-json\/wp\/v2\/categories?post=132"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.shuizilong.com\/house\/wp-json\/wp\/v2\/tags?post=132"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}