leetcode 6. Z 字形变换

leetcode ​​6. Z 字形变换​​

O(n)

class Solution {
public:
    string convert(string s, int numRows) {
        int len = s.length(),i = 0,j;
        while(i < len){
            j = 0;
            for(;j < numRows && i < len;++j,++i)
                v[j] += s[i];
            if(j != numRows)
                break;
            j = numRows - 2;
            while(j > 0 && i < len)
                v[j] += s[i],--j,++i;
        }
        s = "";
        for(i = 0;i < numRows;++i)
            s += v[i];
        return s;
    }
};