题目 链接 题意:给出x数列的定义: $T_0 = a$ $T_1 = b$ $T_n = T_{n-2} \bigoplus T_{n-1} $ 求第 $n$ 项( $0 \leqslant a,b,c \leqslant 10^{18} $) 分析 $n$ 这么大,肯定是常数时间复杂度. 打表找规律,能发现循环节为3. 或者直接推导,$a \bigoplus b = c, \ b \bigoplus c = a, \ c \bigoplus a = b$ #include<bits/stdc…

题目来源:https://leetcode.com/problems/zigzag-conversion/ The string "PAYPALISHIRING" is written in a zigzag pattern on a given number of rows like this: (you may want to display this pattern in a fixed font for better legibility) P A H N A P L S I…

题目链接: http://codeforces.com/gym/101194/attachments https://icpcarchive.ecs.baylor.edu/index.php?option=com_onlinejudge&Itemid=8&page=show_problem&problem=5919 题意: 给出正整数 $N(1 \le N \le 10^5)$,询问对于正整数 $k$,有多少个小于 $2^N$ 的 $2^k-1$ 是 $7$ 的整数倍. 题解: $…

A. Little Pony and Expected Maximum Time Limit: 1 Sec  Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/453/problem/A Description Twilight Sparkle was playing Ludo with her friends Rainbow Dash, Apple Jack and Flutter Shy. But she kept losing.…

6. ZigZag Conversion Medium The string "PAYPALISHIRING" is written in a zigzag pattern on a given number of rows like this: (you may want to display this pattern in a fixed font for better legibility) P A H N A P L S I I G Y I R And then read li…

题目简述 The string "PAYPALISHIRING" is written in a zigzag pattern on a given number of rows like this: (you may want to display this pattern in a fixed font for better legibility) P A H N A P L S I I G Y I R And then read line by line: "PAHNA…

一.题目链接:https://leetcode.com/problems/zigzag-conversion/description/ 二.题目大意: 给定一个字符串和一个数字,将其转换成Zigzag形式后,逐行输出该字符串.所谓的Zigzag形式,具体如下: /*n=numRows Δ=2n-2 1 2n-1 4n-3 Δ= 2 2n-2 2n 4n-4 4n-2 Δ= 3 2n-3 2n+1 4n-5 . Δ= . . . . . Δ= . n+2 . 3n . Δ= n-1 n+1 3n-…

ZigZag Conversion 看了三遍题目才懂,都有点怀疑自己是不是够聪明... 就是排成这个样子啦,然后从左往右逐行读取返回. 这题看起来很简单,做起来,应该也很简单. 通过位置计算行数: P I N A L S I G Y A H R P I 0,0 1,1 2,2 3,3 4,2 5,1 6,0 (期望) 用简单的先思考: P A H N A P L S I I G Y I R 0,0 1,1 2,2 3,3 4,0 %4 (3+1)可以解决正常的 3,1(期望) 特殊的3(2行2排…

https://leetcode.com/problems/zigzag-conversion/ 水题纯考细心 题目:依照Z字形来把一个字符串写成矩阵,然后逐行输出矩阵. O(n)能够处理掉 记i为行数 第0行和第numRow-1行. ans += str[i+k*(numRows*2-2)], k=0,1,2,... 其它, 每一个Z字形(事实上仅仅是一竖一斜两条线)须要加上两个,下标见代码. 特殊处理:numRows=1的时候numRows*2-2==0 ,会死循环的.另外numRows=1…

题意:将字符串排成Z字形. PAHNAPLSIIGYIR 如果是5的话,是这样排的 P     I AP   YR H L G N  SI A    I 于是,少年少女们,自己去找规律吧 提示:每个Z字形的字符串和原字符串的每个字母的位子一一映射 class Solution { public: string convert(string s, int numRows) { string t = s; ) return t; ; ; i < s.size(); i += * numRows -…