[LeetCode]392. Is Subsequence 判斷字串是否為另一字串的子串
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"
"abcde"
while "aec"
is
not).
Example 1:
s = "abc"
, t = "ahbgdc"
Return true
.
Example 2:
s = "axc"
, t = "ahbgdc"
Return false
.
Follow up:
If there are lots of incoming S, say S1, S2, ... , Sk where k >= 1B, and you want to check one by one to see if T has its subsequence. In this scenario, how would you change your code?
Credits:
Special thanks to @pbrother for adding this problem and creating all test cases.
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解法:題目很簡單,判斷字串是否為另一字串的子串,只需遍歷一遍即可,程式碼如下:
#include<iostream> #include<string> using namespace std; bool isSubsequence(string s, string t) { int lenS=s.length(); int lenT=t.length(); int i=0,j=0; while(i<lenS&&j<lenT) { if(s[i]==t[j]) { i++; j++; } else j++; } return i==lenS; } int main() { cout<<isSubsequence("sh","sje")<<endl; }