CODEWITHSUNDEEP
c++arraysfunction
Gary Huang
Gary Huang

Reputation: 11

Removing lead zeroes from an array

I seem to be having issues removing leading zeroes from an array that is created by the user. For example, the program I am writing will ask the user to input a mathematical expression (input received as a string):

Eg : 1234 + 1234

Before going into creating a function to solve this problem, I can't seem to get my array to ignore the leading zeroes. This is because I am switching the user input from string to integer and then positioning these values at the end of the array (constant size is 20). Below is how I convert from string to an integer array.

void stringToInt(int arr[], string value1, int SIZE){
    for (int i = 0; i < SIZE; i++){
         if (arr[i] < 0)
             arr[i] = 0;
         arr[SIZE - 1 - i] = value1[value1.length() - 1 - i] - 48;
}

This is how I tried to remove zeroes:

void removeLeadZeroes(int arr[], string value1, int SIZE){
    bool print = true;
    int carry = 0;
    for (int i = 0; i < (SIZE - 1); i++){
        if (arr[i] == 0
            print = false;
        if (print)
            cout << arr[i];
    }
}

Upvotes: 0

Views: 537

Answers (2)

Ashish K
Ashish K

Reputation: 935

Another simple approach using C. arr2 contains the array without leading zeros. 48 being the ASCII value for 0 can be used to check for zeros in the given array. However I recommend to use built-in atoi as suggested by @Ronald.

#include<stdio.h>

int main(){

        const char *arr1 = "01234+123";
        char *arr2 = (char *)malloc(20);
        int i,j=0;

        for(i=0; arr1[i] != '\0'; i++){
                if((arr1[i] - 48) != 0){
                        arr2[++j] = arr1[i];
                }
        }
return 0;

}

Upvotes: 0

Ronald Mathews
Ronald Mathews

Reputation: 2248

There is a better way for converting strings to integers. There is a buildin function called atoi() in C++. You will have to use stdlib.h header file for this. Converting character array to integer using this function will automatically remove unwanted values in the array.

#include <iostream>
#include <stdlib.h>
using namespace std;

int main() {

    //The character array
    char a[3];

    //The integer variable
    int b;
    gets(a);

    //Converts to integer
    b=atoi(a);

    //To prove that value is an integer and 
    //mathematical operations can be done on it
    cout<<b+2;
    return 0;
}

Hope it helped. Ask if you need any help.

Upvotes: 2

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