【Leetcode】1047. Remove All Adjacent Duplicates In String（第137周周赛）（删除连续字符一次删两个）

待我称王封你为后i 2022-01-30 12:19 145阅读 0赞

Given a string `S` of lowercase letters, a *duplicate removal* consists of choosing two adjacent and equal letters, and removing them.

We repeatedly make duplicate removals on S until we no longer can.

Return the final string after all such duplicate removals have been made. It is guaranteed the answer is unique.

**Example 1:**

Input: "abbaca"
    Output: "ca"
    Explanation: 
    For example, in "abbaca" we could remove "bb" since the letters are adjacent and equal, and this is the only possible move.  The result of this move is that the string is "aaca", of which only "aa" is possible, so the final string is "ca".

解题思路：

发现连续字符立即删除这两连续字符。注意不是让看到连续的全部删除，可以理解为每次只能删两个。

解题思路：

直接模拟栈的操作即可。

class Solution {
    public:
        string removeDuplicates(string S) {
            vector<char> nums;
            for(int i=0;i<S.size();i++){
                if(nums.size()!=0 && nums[nums.size()-1]==S[i]){
                    nums.pop_back();
                }else{
                    nums.push_back(S[i]);
                }
            }
            string ans = "";
            for(int i=0;i<nums.size();i++){
                ans += nums[i];
            }
            return ans;
        }
    };