regular-expression-matching.js

// Given an input string (s) and a pattern (p), implement regular expression matching with support for '.' and '*'.
//
//
// '.' Matches any single character.
// '*' Matches zero or more of the preceding element.
//
//
// The matching should cover the entire input string (not partial).
//
// Note:
//
//
// 	s could be empty and contains only lowercase letters a-z.
// 	p could be empty and contains only lowercase letters a-z, and characters like . or *.
//
//
// Example 1:
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//
// Input:
// s = "aa"
// p = "a"
// Output: false
// Explanation: "a" does not match the entire string "aa".
//
//
// Example 2:
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//
// Input:
// s = "aa"
// p = "a*"
// Output: true
// Explanation: '*' means zero or more of the precedeng element, 'a'. Therefore, by repeating 'a' once, it becomes "aa".
//
//
// Example 3:
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//
// Input:
// s = "ab"
// p = ".*"
// Output: true
// Explanation: ".*" means "zero or more (*) of any character (.)".
//
//
// Example 4:
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//
// Input:
// s = "aab"
// p = "c*a*b"
// Output: true
// Explanation: c can be repeated 0 times, a can be repeated 1 time. Therefore it matches "aab".
//
//
// Example 5:
//
//
// Input:
// s = "mississippi"
// p = "mis*is*p*."
// Output: false
//
//


/**
 * @param {string} s
 * @param {string} p
 * @return {boolean}
 */
var isMatch = function(s, p) {
      var r = s.match(new RegExp(p));
	    if (r === null) return false;
	    if (r[0] === s) return true;
	    return false;
};