力扣日常切题

1.统计字符串中的元音子字符串

题解：三重循环暴力 

AC代码如下：

class Solution {
public:
    int countVowelSubstrings(string word) {
         int sum=0;
        for(int i=0;i<word.size();i++){
        for(int j=i+4;j<word.size();j++) 
        { int a=0,e=0,s=0,o=0,u=0,flag=0;
            for(int k=i;k<=j;k++)
            {
                if(word[k]=='a') a=1;
                else if(word[k]=='e') e=1;
                else if(word[k]=='i') s=1;
                else if(word[k]=='o') o=1;
                else if(word[k]=='u') u=1;
                else 
                {flag=1; break;}
            }
         if(a+e+s+o+u==5&&flag==0)
             sum++;
        }
        }
        return sum;
    }
};

2.所有子字符串中的元音

 AC代码如下：

class Solution {
public:
    long long countVowels(string word) {
        long long sum=0;
        for(int i=0;i<word.size();i++)
        {
        if(word[i]=='a'||word[i]=='e'||word[i]=='i'||word[i]=='o'||word[i]=='u')
        sum+=(i+1)*(word.size()-i);
        }
        return sum;
    }
};