Alibi

My Life is Getting Better

Leetcode[65] Valid Number

13 Dec 2015

###Task1 Validate if a given string is numeric.

Some examples:

"0" => true
" 0.1 " => true
"abc" => false
"1 a" => false
"2e10" => true Note: It is intended for the problem statement to be ambiguous. You should gather all requirements up front before implementing one.

###Java

public class Solution {
    public boolean isNumber(String s) {
        if (s == null || s.length() == 0) {
            return false;
        }
        s = s.trim();
        int i = 0;
        int len = s.length();
        if (i < len && (s.charAt(i) == '-' || s.charAt(i) == '+')) {
            i++;
        }
        boolean isNum = false;
        while (i < len && Character.isDigit(s.charAt(i))) {
            i++;
            isNum = true;
        }
        if (i < len && s.charAt(i) == '.') {
            i++;
            while (i < len && Character.isDigit(s.charAt(i))) {
                i++;
                isNum = true;
            }
        }
        if (isNum && i < len && s.charAt(i) == 'e') {
            i++;
            isNum = false;
            if (i < len && (s.charAt(i) == '+' || s.charAt(i) == '-')) {
                i++;
            }
            while (i < len && Character.isDigit(s.charAt(i))) {
                i++;
                isNum = true;
            }
        }
        return isNum && i == len;
        
    }
}

###Points

Related Posts