Problem Can we fit remaining passengers in the bus using JavaScript

Problem

We need to write a JavaScript function that determines if a bus can accommodate all waiting passengers. The function takes three parameters:

• cap ? the total capacity of people the bus can hold (excluding the driver)

• on ? the number of people currently on the bus (excluding the driver)

• wait ? the number of people waiting to board the bus

If there's enough space for everyone, return 0. Otherwise, return the number of passengers who cannot board.

Solution

The logic is straightforward: calculate total passengers needed (current + waiting) and compare with capacity.

const cap = 120;
const on = 80;
const wait = 65;

const findCapacity = (cap, on, wait) => {
    let totalPassengers = on + wait;
    
    if (totalPassengers > cap) {
        return totalPassengers - cap;  // Return excess passengers
    }
    
    return 0;  // Everyone can fit
};

console.log(findCapacity(cap, on, wait));

Output

25

How It Works

In this example:

• Bus capacity: 120 passengers
• Currently on bus: 80 passengers
• Waiting to board: 65 passengers
• Total needed: 80 + 65 = 145 passengers
• Excess: 145 - 120 = 25 passengers cannot board

Alternative Examples

// Everyone can fit
console.log(findCapacity(50, 20, 25));  // 0

// Exactly at capacity
console.log(findCapacity(100, 60, 40)); // 0

// Overcapacity
console.log(findCapacity(30, 25, 10));  // 5

0
0
5

Optimized Version

We can make the function more concise using Math.max():

const findCapacityOptimized = (cap, on, wait) => {
    return Math.max(0, (on + wait) - cap);
};

console.log(findCapacityOptimized(120, 80, 65)); // 25
console.log(findCapacityOptimized(50, 20, 25));  // 0

25
0

Conclusion

This bus capacity problem demonstrates basic arithmetic logic and conditional statements in JavaScript. The solution efficiently determines passenger overflow by comparing total demand with available capacity.