Leetcode 算法习题 第十四周

392. Is Subsequence

Given a string s and a string t, check if s is subsequence of t.
You may assume that there is only lower case English letters in both s and t. t is potentially a very long (length ~= 500,000) string, and s is a short string (<=100).
A subsequence of a string is a new string which is formed from the original string by deleting some (can be none) of the characters without disturbing the relative positions of the remaining characters. (ie, “ace” is a subsequence of “abcde” while “aec” is not).
Example 1:
s = “abc”, t = “ahbgdc”
Return true.
Example 2:
s = “axc”, t = “ahbgdc”
Return false.

题目大意

判断s 是否为 t 的子序列，不需要连续

我的解答

class Solution {public:    bool isSubsequence(string s, string t) {        int last = 0;        int i,j;        for(i = 0; i < s.size(); i++){            for(j = last; j < t.size(); j++){                if(s[i] == t[j]){                    last = j+1;                    break;                }            }            if(j == t.size()){                return false;            }        }        return true;    }};