leetcode-6- ZigZag Conversion

难度

medium

描述

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   NA P L S I I GY   I   RAnd then read line by line: "PAHNAPLSIIGYIR"Write the code that will take a string and make this conversion given a number of rows:string convert(string text, int nRows);convert("PAYPALISHIRING", 3) should return "PAHNAPLSIIGYIR".

解答

class Solution {public:    string convert(string s, int numRows) {        vector<string> vs(numRows, "");        int n = s.length(), i = 0;        while (i < n) {            for (int j = 0; j < numRows && i < n; j++)                vs[j].push_back(s[i++]);            for (int j = numRows - 2; j >= 1 && i < n; j--)                vs[j].push_back(s[i++]);        }        string zigzag;        for (string v : vs) zigzag += v;        return zigzag;    }};