LeetCode 423. Reconstruct Original Digits from English

解题思路:主要是观察0-9这10 个英文字母的出现规律,先找到每个字符唯一标识的数字,然后找其他出现的字符代表的数字减去唯一标识的字符出现的数字.

class Solution {
public:
string originalDigits(string s) {
vector<int> low_letter(128,0);
vector<int> digit(10,0);
for(int i = 0; i < s.length(); i++){
low_letter[s[i]]++;
}
string res;
digit[0] = low_letter['z'];
digit[2] = low_letter['w'];
digit[4] = low_letter['u'];
digit[6] = low_letter['x'];
digit[8] = low_letter['g'];
digit[1] = low_letter['o'] - digit[0] - digit[2] - digit[4];
digit[3] = low_letter['h'] - digit[8];
digit[5] = low_letter['f'] - digit[4];
digit[7] = low_letter['s'] - digit[6];
digit[9] = low_letter['i'] - digit[5] - digit[6] - digit[8];
for(int i = 0; i < 10; i++){
if(digit[i])
res += string(digit[i],'0'+i);
}
return res;
}
};