Codebuddy week2 solution.

week2.cpp

int pivot(const vector<int> &A){
    int l=0;
    int r=A.size()-1;
    int mid;
    while(l<r){
        mid=(r-l)/2+l;
        if(mid>l && A[mid-1]>A[mid]){
            return mid;
        }
        if(mid<r && A[mid+1]<A[mid]){
            return mid+1;
        }
        if(A[r]>A[mid]){
            r=mid-1;
        }
        else{
            l=mid+1;
        }
    }
    return 0;
}

int bSearch(const vector<int> &A,int l,int r,int key){
    int mid;
    while(l<=r){
        mid=(r-l)/2+l;
        if(A[mid]==key){
            return mid;
        }
        if(A[mid]>key){
            r=mid-1;
        }
        else{
            l=mid+1;
        }
    }
    return -1;
}




int Solution::search(const vector<int> &A, int B) {
    int p=pivot(A);
    int s=bSearch(A,0,p-1,B);
    if(s!=-1)
        return s;
    s=bSearch(A,p,A.size()-1,B);
    return s;
}