Binomial Coefficient

#define     memo(a,b)          memset(a,b,sizeof(a));
#define     foab(i, a, b)      for(__typeof(b) i=(a); i<=(b); i++)
#define     foba(i, a, b)      for(__typeof(b) i=(b); i>=(a); i--)


int binomialCoefficient(int n, int k){
    //Running Time : O(n.k)
    //Memory : O(k)
    //for the shake of O(k) auxiliary space....
    int c[k+1];
    memo(c, 0)//memset
    //nC0 is 1...so (K = 0) => (nCk = 1) [that implies actually]
    c[0] = 1;
    foab(i, 1, n){
        //compute next row of Pascal's triangle using the previous row
        foba(j, 1, (int)min(i, k)){
            //cout<<c[j-1]<<" "<<c[j]<<endl;
            c[j] = c[j-1] + c[j];//iCj = i-1Cj-1 + i-1Cj....the recurrance we use forever
            //cout<<"  "<<c[j]<<endl;
        }

        //cout<<"Pascal's "<<i<<" no Row: "<<endl;
        //foab(j, 0, (int)min(i, k))cout<<c[j]<<" ";
        //cout<<endl;
    }


    return c[k];
}