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{"workbook":{"problemsBrief":"{\"洛谷-P1102\":[\"A-B 数对\",91446,null],\"CodeForces-381A\":[\"Sereja and Dima\",65404,\"\\u003ca style\\u003d\\\"color: black\\\" href\\u003d\\\"https://codeforces.com/contest/381\\\"\\u003eCodeforces Round 223 (Div. 2)\\u003c/a\\u003e\"],\"洛谷-P1147\":[\"连续自然数和\",43995,null],\"POJ-2566\":[\"Bound Found\",2905,\"\\u003cdiv class\\u003d\\\"ptx\\\" lang\\u003d\\\"en-US\\\"\\u003e\\u003ca href\\u003d\\\"http://poj.org/searchproblem?field\\u003dsource\\u0026amp;key\\u003dUlm+Local+2001\\\"\\u003eUlm Local 2001\\u003c/a\\u003e\\u003c/div\\u003e\"],\"POJ-3061\":[\"Subsequence\",14660,\"\\u003cdiv class\\u003d\\\"ptx\\\" lang\\u003d\\\"en-US\\\"\\u003e\\u003ca href\\u003d\\\"http://poj.org/searchproblem?field\\u003dsource\\u0026amp;key\\u003dSoutheastern+Europe+2006\\\"\\u003eSoutheastern Europe 2006\\u003c/a\\u003e\\u003c/div\\u003e\"],\"洛谷-P1638\":[\"逛画展\",23184,null],\"CodeForces-1462A\":[\"Favorite Sequence\",43333,\"\\u003ca style\\u003d\\\"color: black\\\" href\\u003d\\\"https://codeforces.com/contest/1462\\\"\\u003eCodeforces Round 690 (Div. 3)\\u003c/a\\u003e\"]}","joined":false,"groups":{}},"managingGroups":{},"author":"xiejinoi","updateTime":1710051725000,"title":"双指针(尺取法)","dislikeCnt":0,"content":"严格的来说,双指针只能说是是算法中的一种技巧。\n\n双指针指的是在遍历数据的过程当中,不是简单的使用单个指针进行访问,而是使用两个相同方向或者相反方向的指针进行扫描,从而达到处理数据的目的。\n\n双指针(又称尺取法)是一个常用的优化技巧,用来解决序列的区间问题。\n\n两个指针i、j,有两种扫描方向:\n1.反向扫描: i、j方向相反,i从头到尾,j从尾到头,在中间相会。\n2.同向扫描: i、j方向相同,都从头到尾,可以让j跑在i前面。\n\n同向扫描的两个指针称为\"快慢指针\",快慢指针在序列上产生一个大小可变的\"滑动窗口\",有灵活的应用。\n [problem:洛谷-P1147] \n [problem:洛谷-P1102] \n\t [problem:洛谷-P1638] \n\t \t [problem:CodeForces-381A] \n\t\t \t [problem:CodeForces-1462A] \n\t\t [problem:POJ-3061] \n\t\t \t\t [problem:POJ-2566] \n","threadId":185477,"likeCnt":0,"createTime":1710042199000,"isWorkbook":true,"viewCnt":117,"openness":2,"fav":false,"id":4678,"trustable":false}