Problem:###
Implement strStr().
Returns the index of the first occurrence of needle in haystack, or -1 if needle is not part of haystack.
Solution:###
class Solution {
public:
int strStr(string haystack, string needle) {
if(haystack == needle)
return 0;
if(haystack.size() < needle.size())
return -1;
for(int i = 0;i <= haystack.size() - needle.size();i++) //notice the <= here
{
if(haystack.substr(i,needle.size()) == needle)
return i;
}
return -1;
}
};
Memo###
the use of substr
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