C++ program for booth multiplication.

booth-multiplication.cpp

#include<iostream>

using namespace std;

void add(int a[], int x[], int q);

void complement(int a[], int n) {
   int i;
   int x[8] = { NULL };
   x[0] = 1;
   for (i = 0; i < n; i++) {
      a[i] = (a[i] + 1) % 2;
   }
   add(a, x, n);
}

void add(int ac[], int x[], int q) {
   int i, c = 0;
   for (i = 0; i < q; i++) {
      ac[i] = ac[i] + x[i] + c;
      if (ac[i] > 1) {
         ac[i] = ac[i] % 2;
         c = 1;
      }else
      c = 0;
   }
}

void ashr(int ac[], int qr[], int &qn, int q) {
   int temp, i;
   temp = ac[0];
   qn = qr[0];
   cout << "\t\tashr\t\t";
   for (i = 0; i < q - 1; i++) {
      ac[i] = ac[i + 1];
      qr[i] = qr[i + 1];
   }
   qr[q - 1] = temp;
}

void display(int ac[], int qr[], int qrn) {
   int i;
   for (i = qrn - 1; i >= 0; i--)
      cout << ac[i];
   cout << " ";
   for (i = qrn - 1; i >= 0; i--)
      cout << qr[i];
}

int main(int argc, char **argv) {
   int mt[10], br[10], qr[10], sc, ac[10] = { 0 };
   int brn, qrn, i, qn, temp;
   
   cout << "\n--Enter the multiplicand and multipier in signed 2's complement form if negative--";
   cout<<"\n Give space while providing the binary number number between the two bits";
   cout << "\n Number of multiplicand bit=";
   cin >> brn;
   cout << "\nmultiplicand=";

   for (i = brn - 1; i >= 0; i--)
         cin >> br[i]; //multiplicand
      for (i = brn - 1; i >= 0; i--)
         mt[i] = br[i];
      complement(mt, brn);
      cout << "\nNo. of multiplier bit=";
      cin >> qrn;
      sc = qrn;
      cout << "Multiplier=";

      for (i = qrn - 1; i >= 0; i--)
         cin >> qr[i];
      qn = 0;
      temp = 0;
      cout << "qn\tq[n+1]\t\tBR\t\tAC\tQR\t\tsc\n";
      cout << "\t\t\tinitial\t\t";

      display(ac, qr, qrn);
      cout << "\t\t" << sc << "\n";

      while (sc != 0) {
         cout << qr[0] << "\t" << qn;
         if ((qn + qr[0]) == 1) {
            if (temp == 0) {
               add(ac, mt, qrn);
               cout << "\t\tsubtracting BR\t";
               for (i = qrn - 1; i >= 0; i--)
                  cout << ac[i];
               temp = 1;
            }
            else if (temp == 1) {
               add(ac, br, qrn);
               cout << "\t\tadding BR\t";
               for (i = qrn - 1; i >= 0; i--)
                  cout << ac[i];
               temp = 0;
            }
            cout << "\n\t";
            ashr(ac, qr, qn, qrn);
         }
         else if (qn - qr[0] == 0)
            ashr(ac, qr, qn, qrn);
         display(ac, qr, qrn);
         cout << "\t";
         sc--;
         cout << "\t" << sc << "\n";
      }

   cout << "Result=";
   display(ac, qr, qrn);
}

well done