28. Implement strStr()

Implement strStr().

Returns the index of the first occurrence of needle in haystack, or -1 if needle is not part of haystack.


在haystack中找与needle 第一个相匹配的位置。如果找不到，返回-1。

代码如下：

classSolution{public:intstrStr(stringhaystack,stringneedle){if(haystack.size()==0&&needle.size()==0)return0;if(needle.size()==0)return0;if(haystack.size()<needle.size())return-1;for(inti=0;i<haystack.size()-needle.size()+1;i++){boolflag=true;if(needle[0]==haystack[i]){intj=0;for(;j<needle.size();j++){if(needle[j]!=haystack[i+j]){flag=false;break;}}if(flag)returni;}}return-1;}};

2016-08-11 01:02:49