//multiplies as with pen & paper //01-20-2018, Eric Zatarack //Soli Deo Gloria #include #include #include using namespace std; class prepNumz { //prepares real #s as integers public: void desimlz(double r1, int &n1, int &x1) { //floor() truncates decimal and the subtraction isolates it: y = floor(r1); z = r1 - y; while (z != 0.0) { r1 *= 10.0; y = floor(r1); z = r1 - y; ++x1; if (z >= 0.9999) { break; } } //real #s are represented as #-1.9999... and must be rounded up to be considered integer: r1 = ceil(r1); n1 = static_cast(r1); } //close fnxn desimlz private: double y, z; }; class procNumz { //processes #s as separate digits public: void numInArr(int arae1[], int n1) { for (b=0; b<10; ++b) { d = n1 / 10; d *= 10; e = n1 - d; arae1[9-b] = e; n1 /= 10; } } //close fnxn numInArr private: int b, c, d, e; }; class figgerz { //performs the multiplication public: void kalkulait(int arae1[], int arae2[], double r1, double r2, int x1, int x2) { cout << right; cout << setw(20) << r1 << endl; cout << "*" << setw(19) << r2 << endl; for (f=0; f<20; ++f) { cout << "-"; } cout << endl; toatl = 0.0; //begin multiplying: for (g=0; g<10; ++g) { sum = 0; //begins each tabulation row anew for (h=0; h<10; ++h) { //each row and column is multiplied by respective placeholding 10s, 100s, etc.: sum += (arae2[9-g] * arae1[9-h] * static_cast(round(pow(10, h))) * static_cast(round(pow(10, g)))); } //eliminates printout of zero-initializations of arrays: if (sum != 0) { cout << setw(20) << sum << endl; } //collects the answer: toatl += static_cast(sum); } //end multiplying for (i=0; i<20; ++i) { cout << "-"; } cout << endl; //restores decimal of real #s: if (x1 != 0) { toatl /= pow(10, x1); } if (x2 != 0) { toatl /= pow(10, x2); } cout << setw(20) << toatl; } //close fnxn kalkulait private: int f, g, h, i, sum; double toatl; }; int main() { int arae1[10]={0}, arae2[10]={0}, n1, n2, x1=0, x2=0; double r1, r2; prepNumz maikInt1, maikInt2; procNumz sepr8_1, sepr8_2; figgerz abakus; //datuh input: cout << "Entr 2 #s <= 10 djts:\n"; //if both have decimals, limit to 3 each. Output is only up to 6 decimals. cin >> r1 >> r2; //calling classes: maikInt1.desimlz(r1, n1, x1); maikInt2.desimlz(r2, n2, x2); sepr8_1.numInArr(arae1, n1); sepr8_2.numInArr(arae2, n2); abakus.kalkulait(arae1, arae2, r1, r2, x1, x2); cout << flush; return 0; } //end of main //END OF PROGRAMME /* (This version was made on an Android phone in the application cppDroid. Not rounding up real #s led to errors. This was fixed on line 24. The program ran fine in cppDroid but not soloLearn. After I asked for help in Q&A, John Wells offered the solution on line 60: to round up the pow() function. He also suggested removal of duplicate functions which were in the 1st two classes for more efficient memory use and reducing chance of bugs. I also deleted mlTpliKshn2 & mlTpliKshn3, as these were only test programs to help me debug. I hope you like this program.) */

mlTpliKshn.cpp