Programming in Java Week 9 Answers
Q1. Problem statement:
Complete the code to develop a BASIC CALCULATOR that can perform operations like Addition, Subtraction, Multiplication and Division.
Code:-
int i=0;
int j=0;
double ans=0;
char pattern[] = input.toCharArray();
for(int a=0; a<pattern.length; a++)
{
if(pattern[a]=='+')
{
i= Integer.parseInt(input.substring(0,a));
j= Integer.parseInt(input.substring(a+1,pattern.length));
ans = (double)i+j;
}else if(pattern[a]=='-')
{
i= Integer.parseInt(input.substring(0,a));
j= Integer.parseInt(input.substring(a+1,pattern.length));
ans = (double)i-j;
}else if(pattern[a]=='/')
{
i= Integer.parseInt(input.substring(0,a));
j= Integer.parseInt(input.substring(a+1,pattern.length));
ans = (double)i/j;
}else if(pattern[a]=='*')
{
i= Integer.parseInt(input.substring(0,a));
j= Integer.parseInt(input.substring(a+1,pattern.length));
ans = (double)i*j;
}
}
System.out.print(input+" = " + Math.round(ans));
Q2. Problem statement:
Complete the code to develop an ADVANCED CALCULATOR that emulates all the functions of the GUI Calculator as shown in the image.
Code:-
char pattern [] = input.toCharArray();
int f=0;
for(int i=0; i<pattern .length; i++){
pattern [i]=gui_map(pattern [i]);
}
double operand1=0.0;
String o1="";
double operand2=0.0;
String o2="";
double ans=0.0;
outerloop:
for(int i=0; i<pattern .length; i++){
int r=0;
if(pattern [i]=='+'||pattern [i]=='-'||pattern [i]=='/'||pattern [i]=='X'||pattern [i]=='='){
for(int j=0; j<i; j++){
o1+=Character.toString(pattern [j]);
}
operand1=Double.parseDouble(o1);
for(int k=i+1; k<pattern .length; k++){
if(pattern [k]=='='){
f=1;
operand2=Double.parseDouble(o2);
if(pattern [i]=='+'){
ans=operand1+operand2;
}else if(pattern [i]=='-'){
ans=operand1-operand2;
}else if(pattern [i]=='/'){
ans=operand1/operand2;
}else if(pattern [i]=='X'){
ans=operand1*operand2;
}
break outerloop;
}else{
o2+=Character.toString(pattern [k]);
}
}
}
}
if(f==1)
System.out.print(ans);Q3. problem statement
Complete the code to perform a 45 degree anti clock wise rotation with respect to the center of a 5 × 5 2D Array as shown below:
Code:-
char mat[][]= new char[5][5];
for(int L=0;L<5; L++)
{
String input = sc.nextLine();
char seq[] = input.toCharArray();
if(seq.length==5){
for(int i=0;i<5;i++)
{
mat[L][i]=seq[i];
}
}else
{
System.out.print("Wrong Input!");
System.exit(0);
}
}
char tran[][] = new char[5][5];
String outer[]={"00","10","20","30",
"40","41","42","43",
"44","34","24","14",
"04","03","02","01"};
String inner[]={"11","21","31","32",
"33","23","13","12"};
for(int i=0;i<5;i++)
{
for(int j=0;j<5;j++)
{
for(int k=0; k<outer.length; k++)
{
char indices[]=outer[k].toCharArray();
int a = Integer.parseInt(String.valueOf(indices[0]));
int b = Integer.parseInt(String.valueOf(indices[1]));
if(a==i && b==j)
{
if(k==15){k=1;}
else if(k==14){k=0;}
else {k+=2;}
indices=outer[k].toCharArray();
a = Integer.parseInt(String.valueOf(indices[0]));
b = Integer.parseInt(String.valueOf(indices[1]));
tran[a][b] = mat[i][j];
break;
}
}
for(int k=0; k<inner.length; k++)
{
char indices[]=inner[k].toCharArray();
int a = Integer.parseInt(String.valueOf(indices[0]));
int b = Integer.parseInt(String.valueOf(indices[1]));
if(a==i && b==j){
if(k==7){k=0;}
else {k+=1;}
indices=inner[k].toCharArray();
a = Integer.parseInt(String.valueOf(indices[0]));
b = Integer.parseInt(String.valueOf(indices[1]));
tran[a][b] = mat[i][j];
break;
}
}
tran[2][2] = mat[2][2];
}
}
for(int i=0;i<5;i++){
for(int j=0;j<5;j++){
System.out.print(tran[i][j]);
}
System.out.println();
}
Q4. A program needs to be developed which can mirror reflect any 5 × 5 2D character array into its side-by-side reflection. Write suitable code to achieve this transformation as shown below:
Code:-
char act[][]= new char[5][5];
char ref[][]= new char[5][5];
for(int L=0;L<5; L++)
{
String input = sc.nextLine();
char seq[] = input.toCharArray();
if(seq.length==5)
{
for(int i=0;i<5;i++)
{
act[L][i]=seq[i];
}
}
}
for(int i=0; i<5;i++)
{
for(int j=0; j<5;j++)
{
ref[i][j]=act[i][4-j];
}
}
for(int i=0; i<5;i++)
{
for(int j=0; j<5;j++)
{
System.out.print(ref[i][j]);
}
System.out.println();
}
Q5. Write suitable code to develop a 2D Flip-Flop Array with dimension 5 × 5, which replaces all input elements with values 0 by 1 and 1 by 0. An example is shown below:
Code:-
char act[][]= new char[5][5];
for(int L=0;L<5; L++)
{
String input = sc.nextLine();
char pat[] = input.toCharArray();
if(pat.length==5){
for(int i=0;i<5;i++)
{
if(pat[i]=='0' || pat[i]=='1')
{
act[L][i]=pat[i];
if(L==4 && i==4)
flipflop(act);
}
else
{
System.out.print("Only 0 and 1 supported.");
break;
}
}
}else
{
System.out.print("Invalid length");
break;
}
}
}
static void flipflop(char[][] flip)
{
for(int i=0; i<5;i++)
{
for(int j=0; j<5;j++)
{
if(flip[i][j]=='1')
flip[i][j]='0';
else
flip[i][j]='1';
}
}
for(int i=0; i<5;i++)
{
for(int j=0; j<5;j++)
{
System.out.print(flip[i][j]);
}
System.out.println();
}