实现strStr()
一.题目
二.思路
needle
作为外循环,haystack
作为内循环,注意这里 if ((index + needle.length() - 1) > (haystack.length() - 1))
public int strStr(String haystack, String needle) {
if (needle.equals("")) {
return 0;
}
int index = 0;
for (int i = 0; i < needle.length(); i++) {
for (int j = 0; j < haystack.length(); j++) {
if (haystack.charAt(j) == needle.charAt(i)) {
index = j;
if ((index + needle.length() - 1) > (haystack.length() - 1)) {
return -1;
} else if (haystack.substring(index,
index + needle.length()).equals(needle)) {
return index;
}
}
}
}
return -1;
}