{"id":742,"date":"2026-04-18T02:37:23","date_gmt":"2026-04-17T18:37:23","guid":{"rendered":"http:\/\/wordpress.fangt.online\/?p=742"},"modified":"2026-04-18T13:20:29","modified_gmt":"2026-04-18T05:20:29","slug":"p1473-usaco2-3-%e9%9b%b6%e7%9a%84%e6%95%b0%e5%88%97zero-sum","status":"publish","type":"post","link":"http:\/\/wordpress.fangt.online\/index.php\/2026\/04\/18\/p1473-usaco2-3-%e9%9b%b6%e7%9a%84%e6%95%b0%e5%88%97zero-sum\/","title":{"rendered":"[USACO2.3] \u96f6\u7684\u6570\u5217Zero Sum"},"content":{"rendered":"\n<p class=\"wp-block-paragraph\">\u6570\u636e\u4e0d\u5927\uff0c\u53ef\u4ee5\u66b4\u529b<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>#include&lt;bits\/stdc++.h>\nusing namespace std;\nint n;\nbool judge(string s){\n    int ans=0;\n    int num=0;\n    char op='+';\n    for(int i=0;i&lt;=s.length();i++) {\n        if(s&#91;i]==' ') continue;\n        char c=s&#91;i];\n        if(isdigit(c)) num=num*10+(c-'0');\n        else {\n            if(op=='+') ans+=num;\n            else if(op=='-') ans-=num;\n            op=c;\n            num=0;\n        }\n    }\n    return ans==0;\n}\nvoid dfs(int k,string s){\n    if(k==n){\n        s+=to_string(k);\n        if(judge(s)) cout&lt;&lt;s&lt;&lt;\"\\n\";\n    }\n    else{\n\tdfs(k+1,s+to_string(k)+\" \");\n\tdfs(k+1,s+to_string(k)+\"+\");\n\tdfs(k+1,s+to_string(k)+\"-\");\n    }\n}\nint main(){\n    cin>>n;\n    dfs(1,\"\");\n    return 0;\n}<\/code><\/pre>\n","protected":false},"excerpt":{"rendered":"<p>\u6570\u636e\u4e0d\u5927\uff0c\u53ef\u4ee5\u66b4\u529b<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[58],"tags":[],"class_list":["post-742","post","type-post","status-publish","format-standard","hentry","category-st"],"_links":{"self":[{"href":"http:\/\/wordpress.fangt.online\/index.php\/wp-json\/wp\/v2\/posts\/742","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/wordpress.fangt.online\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/wordpress.fangt.online\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/wordpress.fangt.online\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/wordpress.fangt.online\/index.php\/wp-json\/wp\/v2\/comments?post=742"}],"version-history":[{"count":2,"href":"http:\/\/wordpress.fangt.online\/index.php\/wp-json\/wp\/v2\/posts\/742\/revisions"}],"predecessor-version":[{"id":761,"href":"http:\/\/wordpress.fangt.online\/index.php\/wp-json\/wp\/v2\/posts\/742\/revisions\/761"}],"wp:attachment":[{"href":"http:\/\/wordpress.fangt.online\/index.php\/wp-json\/wp\/v2\/media?parent=742"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/wordpress.fangt.online\/index.php\/wp-json\/wp\/v2\/categories?post=742"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/wordpress.fangt.online\/index.php\/wp-json\/wp\/v2\/tags?post=742"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}