#include <stdio.h>
#include <stdlib.h>
#include <time.h>

#define NUM_TRIALS 1000000

int main() {
    int silverCount = 0; // Count of times a silver coin is drawn after a gold coin
    int goldCount = 0; // Count of times a gold coin is drawn first

    // Seed the random number generator
    srand(time(NULL));

    for (int i = 0; i < NUM_TRIALS; i++) {
        // Randomly select a box: 0 = GG, 1 = SS, 2 = GS
        int box = rand() % 3;

        // Randomly select a coin from the chosen box
        int firstCoin;
        if (box == 0) { // Box GG
            firstCoin = 0; // Always gold
        } else if (box == 1) { // Box SS
            firstCoin = 1; // Always silver
        } else { // Box GS
            firstCoin = rand() % 2; // 0 = gold, 1 = silver
        }

        // If the first coin is gold, check for the second coin
        if (firstCoin == 0) {
            goldCount++; // Count the gold coin drawn first

            // Now select the second coin from the same box
            int secondCoin;
            if (box == 0) { // Box GG
                secondCoin = 0; // Always gold
            } else if (box == 1) { // Box SS
                secondCoin = 1; // Always silver
            } else { // Box GS
                secondCoin = 1; // The only other coin is silver
            }

            // If the second coin is silver, increment the silver count
            if (secondCoin == 1) {
                silverCount++;
            }
        }
    }

    // Calculate the probability of drawing a silver coin after a gold coin was drawn first
    double probability = (double)silverCount / goldCount;

    printf("Total trials: %d\n", NUM_TRIALS);
    printf("Gold coins drawn first: %d\n", goldCount);
    printf("Silver coins drawn after a gold coin: %d\n", silverCount);
    printf("Probability of drawing a silver coin after a gold coin: %.2f\n", probability);

    return 0;
}

C Language online compiler

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Read inputs from stdin

OneCompiler's C online editor supports stdin and users can give inputs to programs using the STDIN textbox under the I/O tab. Following is a sample C program which takes name as input and print your name with hello.

#include <stdio.h>
int main()
{
    char name[50];
    printf("Enter name:");
    scanf("%s", name);
    printf("Hello %s \n" , name );
    return 0;
    
}

About C

C language is one of the most popular general-purpose programming language developed by Dennis Ritchie at Bell laboratories for UNIX operating system. The initial release of C Language was in the year 1972. Most of the desktop operating systems are written in C Language.

Key features:

  • Structured Programming
  • Popular system programming language
  • UNIX, MySQL and Oracle are completely written in C.
  • Supports variety of platforms
  • Efficient and also handle low-level activities.
  • As fast as assembly language and hence used as system development language.

Syntax help

Loops

1. If-Else:

When ever you want to perform a set of operations based on a condition if-else is used.

if(conditional-expression) {
   // code
} else {
   // code
}

You can also use if-else for nested Ifs and if-else-if ladder when multiple conditions are to be performed on a single variable.

2. Switch:

Switch is an alternative to if-else-if ladder.

switch(conditional-expression) {    
case value1:    
 // code    
 break;  // optional  
case value2:    
 // code    
 break;  // optional  
...    
    
default:     
 // code to be executed when all the above cases are not matched;    
}

3. For:

For loop is used to iterate a set of statements based on a condition.

for(Initialization; Condition; Increment/decrement){  
  // code  
}

4. While:

While is also used to iterate a set of statements based on a condition. Usually while is preferred when number of iterations are not known in advance.

while(condition) {  
 // code 
}

5. Do-While:

Do-while is also used to iterate a set of statements based on a condition. It is mostly used when you need to execute the statements atleast once.

do {
  // code 
} while (condition);

Arrays

Array is a collection of similar data which is stored in continuous memory addresses. Array values can be fetched using index. Index starts from 0 to size-1.

Syntax

One dimentional Array:

data-type array-name[size];

Two dimensional array:

data-type array-name[size][size];

Functions

Function is a sub-routine which contains set of statements. Usually functions are written when multiple calls are required to same set of statements which increases re-usuability and modularity.

Two types of functions are present in C

  1. Library Functions:

Library functions are the in-built functions which are declared in header files like printf(),scanf(),puts(),gets() etc.,

  1. User defined functions:

User defined functions are the ones which are written by the programmer based on the requirement.

How to declare a Function

return_type function_name(parameters);

How to call a Function

function_name (parameters)

How to define a Function

return_type function_name(parameters) {  
  //code
}