LeetCode065 Valid Number

来源：互联网发布：梦幻古龙服务端源码编辑：程序博客网时间：2024/06/07 19:02

详细见：leetcode.com/problems/valid-number

Java Solution: github

package leetcode;public class P065_ValidNumber {public static void main(String[] args) {System.out.println(new Solution().isNumber("  4e+ "));}/* * 艰难的试错AC * 4 ms * 61.35%  */static class Solution {    public boolean isNumber(String s) {    char[] cs = s.toCharArray();    int sti = 0, eni = cs.length - 1;    while (sti <= eni && cs[sti] == ' ')sti ++;    while (eni >= sti && cs[eni] == ' ')eni --;    if (sti > eni)    return false;    if (sti <= eni && (cs[sti] == '-' || cs[sti] == '+'))    sti ++;    boolean isHasE = false, isHasDot = false, isHasNum = false;    int indexOfE = -1;    for (int i = sti; i <= eni; i ++) {    if (cs[i] == ' ')    return false;    if (cs[i] == 'e' || cs[i] == 'E') {    if (!isHasNum || isHasE || i == sti || i == eni)    return false;    isHasE = true;    indexOfE = i;    if (cs[i + 1] == '-' || cs[i + 1] == '+') {    if (i + 1 == sti)    return false;    i ++;    }    isHasNum = false;    continue;    }    if (cs[i] == '.') {    if (isHasDot)    return false;    isHasDot = true;    if (indexOfE != -1 && indexOfE < i)    return false;    continue;    }    if (! (cs[i] >= '0' && cs[i] <= '9'))    return false;    isHasNum = true;    }        return isHasNum;    }}}

C Solution: github

/*    url: leetcode.com/problems/valid-number    AC 6ms 11.86%*/typedef int bool;/*    sign:        still sign means still true        1: num        2: e        3: dot*/bool isNumber(char* s) {    char c = '\0';    int sign = 0;    int dot_cnt = 0;    int e_cnt = 0;    int has_val = 0;    int si = 0, ei = -1, i = 0;    while (s[ei+1] != '\0') ei ++;    while (s[ei] == ' ') ei --;    while (s[si] == ' ') si ++;    for (i = si; i <= ei ; i++) {        c = s[i];        if (c == '\0') break;        if (c == '-' || c == '+') {            if (i != si && sign != 2)                return 0;            continue;        }        if (c == ' ') {            return 0;        }        //check .(dot)        if (c == '.') {            //has .(dot)            if (dot_cnt != 0) return 0;            if (sign == 2) return 0;            if (e_cnt > 0)  return 0;            dot_cnt = 1;            sign = 3;            continue;        }        //check e        if (c == 'e' || c == 'E') {            //has e            if (e_cnt != 0) return 0;            if (has_val == 0) return 0;            e_cnt = 1;            sign = 2;            continue;        }        if (c >= '0' && c <= '9') {            has_val = 1;            sign = 1;            continue;        }        return 0;    }    return sign == 2 ? 0 : has_val;}int main() {    char* s = "-13. ";    printf("answer is %d\r\n", isNumber(s));    return 0;}

Python Solution: github

#coding=utf-8'''    url: leetcode.com/problems/valid-number    @author:     zxwtry    @email:      zxwtry@qq.com    @date:       2017年4月14日    @details:    Solution: 56ms 86.13%'''class Solution(object):    def isNumber(self, s):        """        :type s: str        :rtype: bool        """        try:            float(s)            return True        except:            return False

0 0