Exponential notation of a decimal number

Given a positive decimal number, find the simple exponential notation (x = a·10^b) of the given number.

Examples:

Input : 100.0
Output : 1E2
Explanation:
The exponential notation of 100.0 is 1E2.

Input :19
Output :1.9E1
Explanation:
The exponential notation of 16 is 1.6E1.

Recommended: Please try your approach on {IDE} first, before moving on to the solution.

Approach:
The simplest way is to find the position of the first non zero digit and the position of the dot. The difference between that positions is the value of b (if the value is positive you should also decrease it by one).

Below is the implementation of the above approach:

// C++ code to find the exponential notation 
#include <bits/stdc++.h> 
using namespace std; 
  
// function to calculate the exponential 
// notation 
void FindExponent(char s[], int n) 
{ 
    int i, j, b, c; 
    for (i = 0; s[i] == '0' || s[i] == '.'; i++) 
        ; 
    for (j = n - 1; s[j] == '0' || s[j] == '.'; j--) 
        ; 
  
    c = find(s, s + n, '.') - s; 
    putchar(s[i]); 
  
    if (i != j) 
        putchar('.'); 
  
    for (int k = i + 1; k <= j; k++) 
        if (s[k] != '.') 
            putchar(s[k]); 
    if (i < c) 
        b = c - i - 1; 
    else
        b = c - i; 
    if (b) 
        printf("E%d", b); 
} 
  
// main function 
int main() 
{ 
    char s[] = "100"; 
    int n = strlen(s); 
    FindExponent(s, n); 
} 

Output:

1E2

My Personal Notes

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Abhishek Sharma 44

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