Question

I wrote the below code to check whether a certin string exists in a text or no. The issue is that match() function always returns false even the pattern exists in the text.

int main(){

    char *text="hello my name is plapla";
    char *patt="my";

    cout<<match(patt,text);

    system("pause");
    return 0;
}

bool match(char* patt,char* text){

    int textLoc=0, pattLoc=0, textStart=0;
    while(textLoc <= (int) strlen(text) && pattLoc <= (int)strlen(patt)){
        if( *(patt+pattLoc) == *(text+textLoc) ){
            textLoc= textLoc+1;
            pattLoc= pattLoc+1;

        }

        else{
            textStart=textStart+1;
            textLoc=textStart;
            pattLoc=0;
        }

    }
    if(pattLoc > (int) strlen(patt))
        return true;
    else return false;
}

Answer 1

Try pattLoc < (int)strlen(patt) in your while loop.
Loop will stop when pattLoc == 2, so you avoid comparing the '\0' of "my" with the ' ' of "hello my name is pala", which set pattloc to 0 and return false.

Or better, use string substr.