[leetcode] 984. String Without AAA or BBB(贪心算法!!!)

原题:

Given two integers A and B, return any string S such that:

• S has length A + B and contains exactly A 'a' letters, and exactly B 'b' letters;
• The substring 'aaa' does not occur in S;
• The substring 'bbb' does not occur in S.

Example 1:

Input: A = 1, B = 2
Output: "abb"
Explanation: "abb", "bab" and "bba" are all correct answers.

Example 2:

Input: A = 4, B = 1
Output: "aabaa"

Note:

1. 0 <= A <= 100
2. 0 <= B <= 100
3. It is guaranteed such an S exists for the given A and B.

 思路:

贪心算法!!!!

 

c++代码实现:

class Solution {
public:
    string strWithout3a3b(int A, int B) {
        string ans="";
        char a='a',b='b';
        if(A<B){
            swap(A,B);
            swap(a,b);
        }
        while(A||B){
            if(A>0) {ans+= a; A--;}
            if(A>B) {ans+= a; A--;}
            if(B>0) {ans+= b; B--;}
        }
        return ans;
    }
};