题目:Implement strStr().
Returns the index of the first occurrence of needle in haystack,
or -1 if needle is not part of haystack.
Returns the index of the first occurrence of needle in haystack,
or -1 if needle is not part of haystack.
意思是:从haystack字符串中查找给定字符串needle第一次出现的位置
代码如下:
class Solution {
public:
int strStr(string haystack, string needle) {
int m = haystack.length(), n = needle.length();
if (!n) return 0;
for (int i = 0; i < m - n + 1; i++) {
int j = 0;
for (; j < n; j++)
if (haystack[i + j] != needle[j])
break;
if (j == n) return i;
}
return -1;
}
};