力扣题:数字与字符串间转换-12.25

力扣题-12.25

[力扣刷题攻略] Re：从零开始的力扣刷题生活

力扣题1：481. 神奇字符串

解题思想：首先将字符串构建出来，然后进行遍历即可

class Solution(object):
    def magicalString(self, n):
        """
        :type n: int
        :rtype: int
        """
        temp = '122'
        num = 1
        i = 2
        if n>3:
            while True:
                temp = temp + int(temp[i])*str(num)
                if num ==1:
                    num = 2
                else:
                    num = 1
                if len(temp)>n:
                    break
                i = i+1
        count = 0
        for i in range(n):
            if temp[i] == '1':
                count +=1
        return count

class Solution {
public:
    int magicalString(int n) {
        std::string temp = "122";
        int num = 1;
        int i = 2;

        if (n > 3) {
            while (true) {
                for (int j = 0; j < temp[i] - '0'; ++j) {
                    temp += std::to_string(num);
                }
                num = (num == 1) ? 2 : 1;
                if (temp.length() > n) {
                    break;
                }
                i++;
            }
        }
        int count = 0;
        for (int i = 0; i < n; i++) {
            if (temp[i] == '1') {
                count++;
            }
        }
        return count;
    }
};