{"id":207767,"date":"2025-07-08T15:27:30","date_gmt":"2025-07-08T07:27:30","guid":{"rendered":"https:\/\/server.hk\/cnblog\/207767\/"},"modified":"2025-07-08T15:27:30","modified_gmt":"2025-07-08T07:27:30","slug":"%e5%90%8c%e6%97%b6%e8%ae%a1%e7%ae%97%e6%a0%91%e5%8f%b6%e6%95%b0%e9%87%8f","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/207767\/","title":{"rendered":"\u540c\u65f6\u8ba1\u7b97\u6811\u53f6\u6570\u91cf"},"content":{"rendered":"

<\/b> <\/p>\n

\u5f53\u524d\u4f4d\u7f6e\uff1a ><\/span> ><\/span> ><\/span> ><\/span> \u540c\u65f6\u8ba1\u7b97\u6811\u53f6\u6570\u91cf<\/span><\/p>\n

\u6765\u6e90\uff1astackoverflow<\/span>
\n2024-04-25 14:51:34<\/span>
\n<\/i>0\u6d4f\u89c8<\/span>
\n<\/i>\u6536\u85cf<\/span> <\/p>\n

\u5728Golang\u5b9e\u6218\u5f00\u53d1\u7684\u8fc7\u7a0b\u4e2d\uff0c\u6211\u4eec\u7ecf\u5e38\u4f1a\u9047\u5230\u4e00\u4e9b\u8fd9\u6837\u90a3\u6837\u7684\u95ee\u9898\uff0c\u7136\u540e\u8981\u5361\u597d\u534a\u5929\uff0c\u7b49\u95ee\u9898\u89e3\u51b3\u4e86\u624d\u53d1\u73b0\u539f\u6765\u4e00\u4e9b\u7ec6\u8282\u77e5\u8bc6\u70b9\u8fd8\u662f\u6ca1\u6709\u638c\u63e1\u597d\u3002\u4eca\u5929\u5c31\u6574\u7406\u5206\u4eab\u300a\u540c\u65f6\u8ba1\u7b97\u6811\u53f6\u6570\u91cf\u300b\uff0c\u804a\u804a\uff0c\u5e0c\u671b\u53ef\u4ee5\u5e2e\u52a9\u5230\u6b63\u5728\u52aa\u529b\u8d5a\u94b1\u7684\u4f60\u3002<\/p>\n

\u95ee\u9898\u5185\u5bb9
\n <\/p>\n

\u6211\u60f3\u4f7f\u7528\u5e76\u53d1\u6a21\u578b\u7f16\u5199\u4e00\u4e2a\u51fd\u6570\uff0c\u4ee5\u9632\u8f93\u5165\u592a\u5927\uff0c\u5e76\u884c\u5904\u7406\u4f1a\u66f4\u6709\u6548\uff0c\u4f46\u5b83\u6c38\u8fdc\u4e0d\u4f1a\u7ed3\u675f\u3002<\/p>\n

\u5047\u8bbe\u6709\u4e00\u4e2a struct<\/code> \u5b9a\u4e49\u4e3a\uff1a<\/p>\n

type tree struct {\n    name     string   `json:\"name\"`\n    subtrees []*tree  `json:\"subtrees,omitempty\"`\n    leaves   []string `json:\"leaves\"`\n}<\/pre>\n
\u6211\u60f3\u7f16\u5199\u4e00\u4e2a\u51fd\u6570\u6765\u8ba1\u7b97\u6574\u4e2a\u9012\u5f52\u7ed3\u6784\u4e2d leaves<\/code> \u7684\u603b\u6570\u3002\u8fd9\u53ef\u4ee5\u901a\u8fc7\u9012\u5f52\u8f7b\u677e\u5b8c\u6210\uff1a<\/p>\n
func (tree *tree) countleaves() int {\n    curr := len(tree.leaves)\n    for _, s := range tree.subtrees {\n        curr += s.countleaves()\n    }\n    return curr\n}<\/pre>\n
\u8fd9\u5f88\u597d\uff0c\u4f46\u662f\u5982\u679c\u7ed3\u6784\u53d8\u5f97\u592a\u5927\uff0c\u6548\u7387\u5c31\u4f1a\u5f88\u4f4e\uff0c\u6240\u4ee5\u6211\u60f3\u5c06\u5176\u91cd\u6784\u4e3a\u5e76\u53d1\u5e76\u4f7f\u7528\u901a\u9053\u3002\u8fd9\u662f\u6211\u7684\u91cd\u6784\u5c1d\u8bd5\uff1a<\/p>\n
func (tree *Tree) CountLeaves() int {\n    var wg sync.WaitGroup\n    ch := make(chan int)\n    defer close(ch)\n    go count(tree, true, ch, &wg)\n\n    var total int\n    wg.Add(1)\n    go func(total *int) {\n        for x := range ch {\n            fmt.Println(x)\n            *total += x\n        }\n        wg.Done()\n    }(&total)\n    wg.Wait()\n\n    return total\n}\n\nfunc count(t *Tree, root bool, ch chan int, wg *sync.WaitGroup) {\n    defer wg.Done()\n    ch <- len(t.Leaves)\n    if t.SubTrees != nil {\n        wg.Add(len(t.SubTrees))\n        for _, s := range t.SubTrees {\n            go count(s, false, ch, wg)\n        }\n        wg.Wait()\n    }\n\n    if root {\n        ch <- -1\n    }\n}<\/pre>\n
\u6211\u5f53\u524d\u80fd\u591f\u901a\u8fc7\u5f53\u524d\u8ba1\u7b97 leaves<\/code> \u603b\u6570\u6240\u9700\u7684\u901a\u9053\u6536\u96c6\u6240\u6709\u6570\u5b57\uff0c\u4f46\u8be5\u51fd\u6570\u6c38\u8fdc\u4e0d\u4f1a\u7ed3\u675f\u3002\u6765\u81ea\u6839 tree<\/code> \u7ed3\u6784\u7684\u7ec8\u6b62\u503c -1<\/code> \u6c38\u8fdc\u4e0d\u4f1a\u901a\u8fc7\u901a\u9053\u63a8\u9001\u6216\u63a5\u6536\uff0c\u6211\u4e0d\u660e\u767d\u4e3a\u4ec0\u4e48\u3002<\/p>\n
\u6709\u4ec0\u4e48\u60f3\u6cd5\u5417\uff1f<\/p>\n
 <\/p>\n
\u89e3\u51b3\u65b9\u6848<\/h2>\n
 <\/p>\n
\u6211\u5f88\u786e\u5b9a\u60a8\u7684 waitgroup<\/code> \u6c38\u8fdc\u4e0d\u4f1a\u83b7\u5f97\u8db3\u591f\u7684 wg.done<\/code> \u8c03\u7528\uff1a<\/p>\n
go func(total *int) {\n    for x := range ch {\n        fmt.println(x)\n        *total += x\n    }\n    wg.done()\n}(&total)<\/pre>\n
\u7531\u4e8e\u60a8\u4ece\u672a\u5173\u95ed ch<\/code>\uff0c\u56e0\u6b64 wg.done<\/code> \u6c38\u8fdc\u4e0d\u4f1a\u5728\u8fd9\u91cc\u88ab\u8c03\u7528\u3002\u6211\u8ba4\u4e3a<\/em>\u5982\u679c\u4f60\u5c06\u5b83\u79fb\u52a8\u5230\u5faa\u73af\u5185\uff1a<\/p>\n
go func(total *int) {\n    for x := range ch {\n        fmt.println(x)\n        *total += x\n         wg.done()\n    }\n}(&total)<\/pre>\n
\u8fd9\u5c06\u89e3\u51b3\u95ee\u9898\u3002<\/p>\n
\u7f16\u8f91\uff1a<\/p>\n
\u5b9e\u9645\u4e0a\uff0c\u6211\u8ba4\u4e3a\u8fd8\u6709\u4e00\u4e2a\u95ee\u9898\uff1a<\/p>\n
defer wg.done()\nch <- len(t.leaves)\nif t.subtrees != nil {\n    wg.add(len(t.subtrees))\n    for _, s := range t.subtrees {\n        go count(s, false, ch, wg)\n    }\n    wg.wait()\n}<\/pre>\n
\u5ef6\u8fdf\u7684 wg.done()<\/code> \u5728\u4f60\u8fd4\u56de\u4e4b\u524d\u4e0d\u4f1a\u88ab\u8c03\u7528\uff0c\u6240\u4ee5\u8fd9\u4e2a wg.wait()<\/code> \u4e5f\u4f1a\u6c38\u8fdc\u7b49\u5f85\u3002\u8fd9\u53ef\u80fd\u662f\uff1a<\/p>\n
ch <- len(t.Leaves)\nif t.SubTrees != nil {\n    wg.Add(len(t.SubTrees))\n    for _, s := range t.SubTrees {\n        go count(s, false, ch, wg)\n    }\n    wg.Done()\n    wg.Wait()\n} else {\n    wg.Done()\n}<\/pre>\n
\u672c\u7bc7\u5173\u4e8e\u300a\u540c\u65f6\u8ba1\u7b97\u6811\u53f6\u6570\u91cf\u300b\u7684\u4ecb\u7ecd\u5c31\u5230\u6b64\u7ed3\u675f\u5566\uff0c\u4f46\u662f\u5b66\u65e0\u6b62\u5883\uff0c\u60f3\u8981\u4e86\u89e3\u5b66\u4e60\u66f4\u591a\u5173\u4e8eGolang\u7684\u76f8\u5173\u77e5\u8bc6\uff0c\u8bf7\u5173\u6ce8\u516c\u4f17\u53f7\uff01<\/p>\n","protected":false},"excerpt":{"rendered":"
\u5f53\u524d\u4f4d\u7f6e\uff1a > > ...<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[4925],"tags":[],"class_list":["post-207767","post","type-post","status-publish","format-standard","hentry","category-4925"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/207767","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/comments?post=207767"}],"version-history":[{"count":0,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/207767\/revisions"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=207767"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=207767"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=207767"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}