[Golang] Coin sums - Problem 31 - Project Euler

3 years ago

source link: http://siongui.github.io/2018/10/07/go-coin-sums-problem-31-project-euler/
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[Golang] Coin sums - Problem 31 - Project Euler

October 07, 2018

Problem: [1]

In England the currency is made up of pound, £, and pence, p, and there are eight coins in general circulation:

1p, 2p, 5p, 10p, 20p, 50p, £1 (100p) and £2 (200p).

It is possible to make £2 in the following way:

1×£1 + 1×50p + 2×20p + 1×5p + 1×2p + 3×1p

How many different ways can £2 be made using any number of coins?

Solution:

73682

My solution is ugly, which uses the brute-force method.

Run Code on Go Playground

package main

import (
      "fmt"
)

func main() {
      numberOfWays := 0

      // loop for £2 (200p)
      for a := 0; a <= 1; a++ {
              sumA := a * 200
              if sumA >= 200 {
                      if sumA == 200 {
                              fmt.Println("£2 = £2 *", a)
                              numberOfWays++
                      }
                      break
              }

              // loop for £1 (100p)
              for b := 0; b <= 2; b++ {
                      sumB := sumA + b*100
                      if sumB >= 200 {
                              if sumB == 200 {
                                      fmt.Println("£2 = £2 *", a, "+ £1 *", b)
                                      numberOfWays++
                              }
                              break
                      }

                      // loop for 50p
                      for c := 0; c <= 4; c++ {
                              sumC := sumB + c*50
                              if sumC >= 200 {
                                      if sumC == 200 {
                                              fmt.Println("£2 = £2 *", a, "+ £1 *", b, "+ 50p *", c)
                                              numberOfWays++
                                      }
                                      break
                              }

                              // loop for 20p
                              for d := 0; d <= 10; d++ {
                                      sumD := sumC + d*20
                                      if sumD >= 200 {
                                              if sumD == 200 {
                                                      fmt.Println("£2 = £2 *", a, "+ £1 *", b, "+ 50p *", c, "+ 20p *", d)
                                                      numberOfWays++
                                              }
                                              break
                                      }

                                      // loop for 10p
                                      for e := 0; e <= 20; e++ {
                                              sumE := sumD + e*10
                                              if sumE >= 200 {
                                                      if sumE == 200 {
                                                              fmt.Println("£2 = £2 *", a, "+ £1 *", b, "+ 50p *", c, "+ 20p *", d, "+ 10p *", e)
                                                              numberOfWays++
                                                      }
                                                      break
                                              }

                                              // loop for 5p
                                              for f := 0; f <= 40; f++ {
                                                      sumF := sumE + f*5
                                                      if sumF >= 200 {
                                                              if sumF == 200 {
                                                                      fmt.Println("£2 = £2 *", a, "+ £1 *", b, "+ 50p *", c, "+ 20p *", d, "+ 10p *", e, "+ 5p *", f)
                                                                      numberOfWays++
                                                              }
                                                              break
                                                      }

                                                      // loop for 2p
                                                      for g := 0; g <= 100; g++ {
                                                              sumG := sumF + g*2
                                                              if sumG >= 200 {
                                                                      if sumG == 200 {
                                                                              fmt.Println("£2 = £2 *", a, "+ £1 *", b, "+ 50p *", c, "+ 20p *", d, "+ 10p *", e, "+ 5p *", f, "+ 2p *", g)
                                                                              numberOfWays++
                                                                      }
                                                                      break
                                                              }

                                                              // loop for 1p
                                                              for h := 0; h <= 200; h++ {
                                                                      sumH := sumG + h*1
                                                                      if sumH >= 200 {
                                                                              if sumH == 200 {
                                                                                      fmt.Println("£2 = £2 *", a, "+ £1 *", b, "+ 50p *", c, "+ 20p *", d, "+ 10p *", e, "+ 5p *", f, "+ 2p *", g, "+ 1p *", h)
                                                                                      numberOfWays++
                                                                              }
                                                                              break
                                                                      }
                                                              }
                                                      }
                                              }
                                      }
                              }
                      }
              }
      }

      fmt.Println("number of ways:", numberOfWays)
}

Test on: