Java for LeetCode 065 Valid Number
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.
解题思路:
本题边界条件颇多"1.", ".34","1.1e+.1"也是正确的。解题方法是先trim一下,然后按照e进行划分,然后分别对e前后进行判断JAVA实现如下:
public boolean isNumber(String s) { s = s.trim(); String[] splitArr = s.split("e"); if (s.length() == 0 || s.charAt(0) == 'e' || s.charAt(s.length() - 1) == 'e' || splitArr.length > 2) return false; for (int k = 0; k < splitArr.length; k++) { String str = splitArr[k]; boolean isDecimal = false; if (str.charAt(0) == '-' || str.charAt(0) == '+') str = str.substring(1); if (str.length() == 0) return false; for (int i = 0; i < str.length(); i++) { if ('0' <= str.charAt(i) && str.charAt(i) <= '9') continue; else if (str.charAt(i) == '.' && !isDecimal) { if (k == 0 && str.length() > 1) isDecimal = true; else return false; } else return false; } } return true; }