[LeetCode 解题报告]003.Longest Substring Without Repeating Characters

Description:

Given a string, find the length of the longest substring without repeating characters.

Examples:

Given

"abcabcbb"

, the answer is

"abc"

, which the length is 3.

Given

"bbbbb"

, the answer is

"b"

, with the length of 1.

Given

"pwwkew"

, the answer is

"wke"

, with the length of 3. Note that the answer must be a
substring,

"pwke"

is a subsequence and not a substring.

算法思想：思想类似[编程之美-02]字符串的包含问题
中的高效解法，向int数组进行哈希。

class Solution {
public:
int lengthOfLongestSubstring(string s) {

int maxLength = 0, count[128] = {0}, i, j;

for(i = 0, j = 0; i < s.length(); i++) {

if(count[s[i]] == 1) {
maxLength = max(maxLength, i-j);
while(s[j] != s[i]) {
count[s[j]] = 0;
j ++;
}
j ++;
}
else
count[s[i]] = 1;
}

return max(maxLength, i-j);
}
};