Description
Given an array of strings patterns and a string word, return the number of strings in patterns that exist as a substring in word.
A substring is a contiguous sequence of characters within a string.
Examples
Input: patterns = ["a","abc","bc","d"], word = "abc"
Output: 3
Explanation:
- "a" appears as a substring in "abc".
- "abc" appears as a substring in "abc".
- "bc" appears as a substring in "abc".
- "d" does not appear as a substring in "abc".
3 of the strings in patterns appear as a substring in word.
Input: patterns = ["a","b","c"], word = "aaaaabbbbb"
Output: 2
Explanation:
- "a" appears as a substring in "aaaaabbbbb".
- "b" appears as a substring in "aaaaabbbbb".
- "c" does not appear as a substring in "aaaaabbbbb".
2 of the strings in patterns appear as a substring in word.Solution
用String的indexOf很容易就能解决。
var numOfStrings = function(patterns, word) {
let num = 0;
for(let i = 0; i < patterns.length; i++) {
if(word.indexOf(patterns[i]) > -1) {
num += 1;
}
}
return num;
}如果自己实现indexOf方法：
function myIndexOf(str, word) {
let _str = str.split(''), num = -1, _l = +word.length; // word.length需要转成Number
for(let i in _str) {
if(_str[i] === word[0]) {
let flag = true, limit = Number(i) + _l;
for(let j = i; j < limit; j++) {
if(_str[j] !== word[j - i]) {
flag = false;
break;
}
}
if(flag) {
num = i;
break;
}
}
}
return num;
}Result
Accepted
82/82 cases passed (146 ms)
Your runtime beats 5.83 % of javascript submissions
Your memory usage beats 89.81 % of javascript submissions (39.6 MB)
