Probability of rain on N+1th day in C++

Given with an array containing 0’s and 1’s where 0’s represents no rain and 1’s represent rainy day. The task is to calculate the probability of rain on N+1th day.

To calculate the probability of rain on N+1th day we can apply the formula

Total number of rainy days in the set / total number of days in a

Input 

arr[] = {1, 0, 0, 0, 1 }

Output 

probability of rain on n+1th day : 0.4

Explanation 

total number of rainy and non-rainy days are: 5 Total number of rainy days represented by 1 are: 2 Probability of rain on N+1th day is: 2 / 5 = 0.4

Input 

arr[] = {0, 0, 1, 0}

Output 

probability of rain on n+1th day : 0.25

Explanation 

total number of rainy and non-rainy days are: 4 Total number of rainy days represented by 1 are: 1 Probability of rain on N+1th day is: 1 / 4 = 0.25

Approach used in the given program is as follows

• Input the elements of an array

• Input 1 for representing rainy day

• Input 0 for representing non-rainy day

• Calculate the probability by applying the formula given above

• Print the result

Algorithm

Start Step 1→ Declare Function to find probability of rain on n+1th day    float probab_rain(int arr[], int size)       declare float count = 0, a       Loop For int i = 0 and i < size and i++          IF (arr[i] == 1)             Set count++          End       End       Set a = count / size       return a step 2→ In main()    Declare int arr[] = {1, 0, 0, 0, 1 }    Declare int size = sizeof(arr) / sizeof(arr[0])    Call probab_rain(arr, size) Stop

Example

 Live Demo

#include <bits/stdc++.h> using namespace std; //probability of rain on n+1th day float probab_rain(int arr[], int size){    float count = 0, a;    for (int i = 0; i < size; i++){       if (arr[i] == 1)          count++;       }       a = count / size;       return a; } int main(){    int arr[] = {1, 0, 0, 0, 1 };    int size = sizeof(arr) / sizeof(arr[0]);    cout<<"probability of rain on n+1th day : "<<probab_rain(arr, size);    return 0; }

Output

If run the above code it will generate the following output −

probability of rain on n+1th day : 0.4