题目描述

替换空格

样例

class Solution {
public:
    string replaceSpace(string s) {
        int len = 0;
        for (auto x: s) {
            if (x == ' ') 
                len += 3;
            else
                len++;
        }

        int i = s.size() - 1, j = len - 1;
        s.resize(len);

        while (i >= 0) {
            if (s[i] == ' ') {
                s[j--] = '0';
                s[j--] = '2';
                s[j--] = '%';
            } else {
                s[j--] = s[i];
            }
            i--;
        }
        return s;
    }
};