ds-algo-study/DS-n-Algos/Dynamic-Programming/popular-problems/CoinChange.js

Just experimenting with publishing a package

function change( coins, amount ) {
  const combinations = new Array( amount + 1 ).fill( 0 )
  combinations[ 0 ] = 1

  for ( let i = 0; i < coins.length; i++ ) {
    const coin = coins[ i ]

    for ( let j = coin; j < amount + 1; j++ ) {
      combinations[ j ] += combinations[ j - coin ]
    }
  }
  return combinations[ amount ]
}

function minimumCoins( coins, amount ) {
  // minimumCoins[i] will store the minimum coins needed for amount i
  const minimumCoins = new Array( amount + 1 ).fill( 0 )

  minimumCoins[ 0 ] = 0

  for ( let i = 1; i < amount + 1; i++ ) {
    minimumCoins[ i ] = Number.MAX_SAFE_INTEGER
  }
  for ( let i = 1; i < amount + 1; i++ ) {
    for ( let j = 0; j < coins.length; j++ ) {
      const coin = coins[ j ]
      if ( coin <= i ) {
        const subRes = minimumCoins[ i - coin ]
        if ( subRes !== Number.MAX_SAFE_INTEGER && subRes + 1 < minimumCoins[ i ] ) {
          minimumCoins[ i ] = subRes + 1
        }
      }
    }
  }
  return minimumCoins[ amount ]
}

function main() {
  const amount = 12
  const coins = [ 2, 4, 5 ]
  console.log( 'Number of combinations of getting change for ' + amount + ' is: ' + change( coins, amount ) )
  console.log( 'Minimum number of coins required for amount :' + amount + ' is: ' + minimumCoins( coins, amount ) )
}

main()