C language force to deduct the length of the last word of the 58th question.Traverse from back to front

58. Length of last word

You are given a string s consisting of several words separated by some space characters before and after them.Returns the length of the last word in the string.

Word is the largest substring consisting of only letters and not containing any space characters.

Example 1:

Enter:s = "Hello World"Output:5Explanation: The last word is "World" and has a length of 5.

Example 2:

Enter:s = " fly me to the moon "Output:4Explanation: The last word is "moon" and has a length of 4.

Example 3:

Enter:s = "luffy is still joyboy"Output:6Explanation: The last word is "joyboy" of length 6.

Tip:

• 1 <= s.length <= 104
• s consists of only English letters and spaces ' '
• s contains at least one word

The topic is relatively simple in general

The question requires to get the length of the last word in the string. You can traverse the string in reverse, find the last word and calculate its length.

Because at least one word exists in the string, there must be letters in the string.First find the last letter in the string, which is the last letter of the last word.

Continue traversing the string in reverse, starting from the last letter, until a space is encountered or the beginning of the string is reached.Each letter traversed is a letter in the last word, so the number of letters traversed is the length of the last word.

int lengthOfLastWord(char *s){int a = 0; //word lengthint i = 0;int len ​​= strlen(s); //string lengthif(len == 1) return 1;for(i = len - 1; i >= 0; i--){if(s[i] != ' '){a++;if(i > 0)if(s[i - 1] == ' ')break;}}return a;}