/*

strStr

Returns the position of the first

occurrence of string target in string source,

or -1 if target is not part of source.

int strStr(String source, String target) {

//…

}

//http://lintcode.com/problem/strstr/

*/

class Solution {

public:

/**

* Returns a index to the first occurrence of target in source,

* or -1 if target is not part of source.

* @param source string to be scanned.

* @param target string containing the sequence of characters to match.

*/

int strStr(const char *source, const char *target) {

if (source == NULL || target == NULL) {

return -1;

}

for (int i = 0; i < strlen(source) - strlen(target) + 1; ++i) {

int j = 0;

for (; j < strlen(target); ++j) {

if (source[i + j] != target[j]) {

break;

}

}

if (j == strlen(target)) {

return i;

}

}

return -1;

}

};