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  1. package main
  2.  
  3. 	import (
  4. 		"bytes"
  5. 		"fmt"
  6. 	)
  7.  
  8. 	func main() {
  9. 		CountdownSolver(Pop([]int{1, 3, 7, 6, 8, 3, 250}))
  10. 		CountdownSolver(Pop([]int{25, 100, 9, 7, 3, 7, 881}))
  11. 		CountdownSolver(Pop([]int{6, 75, 3, 25, 50, 100, 952}))
  12. 	}
  13.  
  14. 	func CountdownSolver(s int, a []int) {
  15. 		c := make([]int, len(a))
  16. 		m := make(map[string]bool)
  17.  
  18. 		for i := 0; i < len(a); {
  19. 			if i == 0 {
  20. 				if _, ok := m[AToS(a)]; !ok {
  21. 					m[AToS(a)] = true
  22. 					if eq, ok := Solve(s, a); ok {
  23. 						fmt.Println(eq, "=", s)
  24. 					}
  25. 				}
  26. 			}
  27.  
  28. 			if c[i] < i {
  29. 				if i%2 == 0 {
  30. 					a[0], a[i] = a[i], a[0]
  31. 				} else {
  32. 					a[i], a[c[i]] = a[c[i]], a[i]
  33. 				}
  34.  
  35. 				c[i]++
  36. 				i = 0
  37. 			} else {
  38. 				c[i] = 0
  39. 				i++
  40. 			}
  41. 		}
  42. 	}
  43.  
  44. 	func AToS(v []int) string {
  45. 		var buffer bytes.Buffer
  46.  
  47. 		for _, e := range v {
  48. 			buffer.WriteString(fmt.Sprint(e, ","))
  49. 		}
  50.  
  51. 		return buffer.String()
  52. 	}
  53.  
  54. 	func Solve(s int, p []int) (string, bool) {
  55. 		ops := GetOperators()
  56.  
  57. 		for _, op := range ops {
  58. 			if ApplyOps(p, op) == s {
  59. 				return GetEq(p, op), true
  60. 			}
  61. 		}
  62. 		return "", false
  63. 	}
  64.  
  65. 	func GetOperators() [][]int {
  66. 		var res [][]int
  67. 		for i := 0; i < 4; i++ {
  68. 			for j := 0; j < 4; j++ {
  69. 				for k := 0; k < 4; k++ {
  70. 					for l := 0; l < 4; l++ {
  71. 						for m := 0; m < 4; m++ {
  72. 							res = append(res, []int{i, j, k, l, m})
  73. 						}
  74. 					}
  75. 				}
  76. 			}
  77. 		}
  78. 		return res
  79. 	}
  80.  
  81. 	func ApplyOps(p []int, op []int) int {
  82. 		s := p[0]
  83. 		for i := 1; i < len(p); i++ {
  84. 			s = ApplyOp(s, p[i], op[i-1])
  85. 		}
  86. 		return s
  87. 	}
  88.  
  89. 	func ApplyOp(a int, b int, op int) int {
  90. 		switch op {
  91. 		case 0:
  92. 			return a + b
  93. 		case 1:
  94. 			return a - b
  95. 		case 2:
  96. 			return a * b
  97. 		case 3:
  98. 			return a / b
  99. 		}
  100. 		return 0
  101. 	}
  102.  
  103. 	func GetEq(p []int, op []int) string {
  104. 		var buffer bytes.Buffer
  105.  
  106. 		buffer.WriteString(fmt.Sprint(p[0]))
  107.  
  108. 		for i := 1; i < len(p); i++ {
  109. 			buffer.WriteString(fmt.Sprint(" ", GetOp(op[i-1]), " ", p[i]))
  110. 		}
  111.  
  112. 		return buffer.String()
  113. 	}
  114.  
  115. 	func GetOp(op int) string {
  116. 		switch op {
  117. 		case 0:
  118. 			return "+"
  119. 		case 1:
  120. 			return "-"
  121. 		case 2:
  122. 			return "*"
  123. 		case 3:
  124. 			return "/"
  125. 		}
  126. 		return ""
  127.  
  128. 	}
  129.  
  130. 	func Pop(a []int) (int, []int) {
  131. 		return a[len(a)-1], a[:len(a)-1]
  132. 	}
Success #stdin #stdout 0.12s 8848KB
comments ()
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Standard input is empty
stdout
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3 + 3 * 7 + 1 * 6 - 8 = 250
3 + 8 * 7 + 6 * 3 + 1 = 250
8 + 3 * 7 + 6 * 3 + 1 = 250
7 + 100 * 25 - 9 / 3 - 7 = 881
100 + 7 * 25 - 9 / 3 - 7 = 881
7 / 7 + 100 * 9 - 25 - 3 = 881
25 - 9 * 7 * 7 + 100 - 3 = 881
25 - 9 * 7 * 7 - 3 + 100 = 881
7 * 3 + 100 * 7 + 25 + 9 = 881
3 * 7 + 100 * 7 + 25 + 9 = 881
7 / 7 + 100 * 9 - 3 - 25 = 881
3 * 7 + 100 * 7 + 9 + 25 = 881
7 * 3 + 100 * 7 + 9 + 25 = 881
25 * 100 / 3 + 75 - 6 + 50 = 952
100 * 25 / 3 + 75 - 6 + 50 = 952
100 * 25 / 3 - 6 + 75 + 50 = 952
25 * 100 / 3 - 6 + 75 + 50 = 952
25 * 100 / 3 - 6 + 50 + 75 = 952
100 * 25 / 3 - 6 + 50 + 75 = 952
100 * 25 / 3 + 50 - 6 + 75 = 952
25 * 100 / 3 + 50 - 6 + 75 = 952
3 + 100 * 75 * 6 / 50 + 25 = 952
100 + 3 * 75 * 6 / 50 + 25 = 952
100 + 6 * 75 * 3 - 50 / 25 = 952
6 + 100 * 75 * 3 - 50 / 25 = 952
100 + 3 * 6 * 75 / 50 + 25 = 952
3 + 100 * 6 * 75 / 50 + 25 = 952
6 + 100 * 3 * 75 - 50 / 25 = 952
100 + 6 * 3 * 75 - 50 / 25 = 952
100 * 25 / 3 + 75 + 50 - 6 = 952
25 * 100 / 3 + 75 + 50 - 6 = 952
25 * 100 / 3 + 50 + 75 - 6 = 952
100 * 25 / 3 + 50 + 75 - 6 = 952
https://ideone.com/58eu3V
language:
Go (go 1.12.1)
created:
7 years ago
visibility:
public

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