Implement strStr().
Returns the index of the first occurrence of needle in haystack, or -1 if needle is not part of haystack.
Seen this question in a real interview before?
題意:返回一個字符串,在另一個字符串中的位置脱吱,如果沒有的話,就返回-1。
c++:
class Solution {
public:
int strStr(std::string haystack, std::string needle) {
int len = needle.size();
if (haystack.size() < len) return -1;
for (int idx=0; idx <= haystack.size()- len; idx++){
if (std::string (haystack.begin()+idx, haystack.begin()+idx+len) == needle) return idx;
}
return -1;
}
};