Code in C HELP!

Part 2:

A safe calculator (100points)

In this project, you will write a safe signed integer calculator.

As with Part 1, some of the code is completed for you and there are descriptions and comments to help.

You should not use any arithmetic operators, except simple assignment, or increment and decrement operators in your code.

The _add(), an add function that only uses bitwise operators, and add(), a safe add function that detects and reports overflow and underflow errors, are crucial to the other functions.

The seven remaining functions either directly or indirectly depend on _add() and add(). Code these functions to in their order to maintain functional dependencies.

Use the main function to test each function before continuing to the next function.

Provided Code:

/* Safe integer calculator - warns if an overflow or underflow error occurs.

Menu Negation Safe unsigned ops Safe signed ops Arithmetic without + - * / % ++ or --

Code the functions below and uncomment the code in main() when completed.

Code the functions in order as they appear. Subsequent functions depend on previous functions. You cannot use any math operators (+ - * / % ++ or --) except simple assignment (=). However, you may use relational and logical operators.

The _add() function should only use bitwise operators. All other functions can call functions necessary to complete the required operation. I added some hints above functions.

*/

#include

// Prototypes int _add(int a, int b); int add(int a, int b); int sub(int a, int b); int neg(int a); int mul(int a, int b); int div(int a, int b); int mod(int a, int b); int pow(int a, int b); int convert(char *input);

// Main int main(int argc, char *argv[]){

int res = 0; // Cumulative result - running total int n = 0; // For number conversion from input string char input[50]; // Input string input[0] = '\0'; // Put null in operator char so loop works

// Write code here to test your functions // Uncomment code below when done

// Loop until quit is selected /* while(input[0] != 'q' && input[0] != 'Q'){ // Show menu choices menu(); // Print prompt with running total printf(" res = %d > ", res); // Get input string gets(input); // Clear screen system("cls");

// Switch on operator char input[0] switch (input[0]){ case '+': res = add(res, convert(input)); break; case '-': res = sub(res, convert(input)); break; case '*': res = mul(res, convert(input)); break; case '/': res = div(res, convert(input)); break; case '%': res = mod(res, convert(input)); break; case '~': res = neg(res); break; case '^': res = pow(res, convert(input)); break; case 'c': case 'C': res = 0; break; case 'q': case 'Q': printf("Good-bye! "); break; default: printf("Enter a valid operator and operand ");

}

} */

return 0; }

// Show menu choices void menu(){ printf(" Safe Integer Calculator "); printf("+ x to add "); printf("- x to subtract "); printf("* x to multiply "); printf("/ x to divide "); printf("%% x to modulus "); printf("~ x to negate "); printf("^ x to raise by power x "); printf("c x to clear result "); printf("q x to quit "); return; }

/* This function should only use bitwise operators and relational operators */ // Add operation using only bitwise operators int _add(int a, int b){ // Loop until b is zero

// Find carry 1 bits - a AND b assign to carry

// Find non carry 1 bits - a XOR b assign to a

// Multiply carry by 2 by shift and assign to b

return a; }

/* Safe add() should call _add() and check for both overflow and underflow errors. */ // Safe add operation int add(int a, int b){ // Declare int for result int res = 0; // Call to _add() a and b and assign to result

// Check for overflow - look at page 90 in book

// Check for underflow - look at page 90 in book

return res; }

/* Negate a by using a bitwise operator and safe add(). Look on page 95 in book. Replace the zero with an expression that solves this. */ // Define negation with ~ and safe add int neg(int a){ // Return negation of a and add 1 return 0; // Replace 0 with code }

/* Remember that subtraction is the same as addition if you negate one of the operands. Replace the zero with an expression that solves this. */ // Define safe subtract by safe add - negate b int sub(int a, int b){ return 0; // Replace 0 with code }

/* Safe mul() uses an iterative call to safe add() to calculate a product. Remember that 5 x 4 = 5 + 5 + 5 + 5 = 20 */ // Define safe multiply by calling safe add b times int mul(int a, int b){ // Declare and initialize cumulative result int res = 0; // Declare sign of product - initially assume positive

// For efficiency - smaller number should be multiplier

// Absolute value of a and flip sign

// Absolute value of b and flip sign

// Accumulate result

// Set sign to output

return res; }

/* Safe div() repeatedly subtracts b from a, counting the number of subtractions until a < b, which it returns. */ // Define safe divide by calling safe subtract b times int div(int a, int b){ // Declare int to count how many times can b be subtracted from a int cnt = 0; // Declare sign

// Absolute value of a and flip sign

// Absolute value of b and flip sign

// loop to calculate how many times can b be subtracted from a

// Set sign to output

return cnt; }

/* Safe mod() repeatedly subtracts b from a until a < b, returning a. */ // Define safe modulus by calling safe subtract int mod(int a, int b){ // Absolute value of a

// Absolute value of b

// Find remainder by repeated subtraction a - b

return a; }

/* Safe pow() calculates as the math pow function but only uses the safe operations. res = n^exp Loop until exp is zero res = res * n exp = exp - 1 Remember the special case for n^0

*/ // Define safe pow by calling safe multiply exp times int pow(int n, int exp){ // Declare int for result of n^exp int res = 0; // Loop and multiply to calculate n^exp

return res; }

/* This function extracts the integer value from the input string. If input = "+ -123", res = -123. If input = "* 987654", res = 987654. The best way to solve complicated problems is to work them out on paper first. */ // Extract the integer from the input string and convert to int int convert(char *input){ // Declare int for result extracted from input int res = 0; // Declare int for sign of result

// Declare two iterators

// Declare a buffer for numeric chars

// Set error to zero - no error found yet

// Check for space in element 1

// Check for negative integer at element 2

// Loop to copy all numeric chars to buffer // i is iterator for input string and should start at first numeric char // j is iterator for buffer where numeric chars are copied // This must test for chars between 0 and 9

// i gets position of last numeric char in buffer

// j is now used for pow function - start at zero

// Construct integer from buffer using pow j increases and i decreases

// Set sign for output return res; }