update

oj/360-2019-spring/24point.js

@@ -1,43 +1,67 @@
-const eps = 0.000001
-
-class Operation {
-    constructor(val, rank, exp) {
-        this.val = val
-        this.rank = rank
-        this.exp = exp
-    }
-
-    plus(that) {
-        return new Operation(this.val + that.val, 0, `${this.exp}+${that.exp}`)
-    }
-
-    minus(that) {
-        let exp
-        if (that.rank === 0) exp = `${this.exp}-(${that.exp})`
-        else exp = `${this.exp}-${that.exp}`
-        return new Operation(this.val - that.val, 0, exp)
+function solve24point(...numbers) {
+    class Operation {
+        constructor(val, rank, exp) {
+            this.val = val
+            this.rank = rank
+            this.exp = exp
+        }
+    
+        plus(that) {
+            return new Operation(this.val + that.val, 0, `${this.exp}+${that.exp}`)
+        }
+    
+        minus(that) {
+            let exp
+            if (that.rank === 0) exp = `${this.exp}-(${that.exp})`
+            else exp = `${this.exp}-${that.exp}`
+            return new Operation(this.val - that.val, 0, exp)
+        }
+    
+        mult(that) {
+            let exp
+            if (this.rank === 0 && that.rank === 0) exp = `(${this.exp})*(${that.exp})`
+            else if (this.rank === 0) exp = `(${this.exp})*${that.exp}`
+            else if (that.rank === 0) exp = `${this.exp}*(${that.exp})`
+            else exp = `${this.exp}*${that.exp}`
+            return new Operation(this.val * that.val, 1, exp)
+        }
+    
+        div(that) {
+            let exp
+            if (this.rank === 0 && that.rank !== 2) exp = `(${this.exp})/(${that.exp})`
+            else if (this.rank === 0) exp = `(${this.exp})/${that.exp}`
+            else if (that.rank !== 2) exp = `${this.exp}/(${that.exp})`
+            else exp = `${this.exp}/${that.exp}`
+            return new Operation(this.val / that.val, 1, exp)
+        }
     }
 
-    mult(that) {
-        let exp
-        if (this.rank === 0 && that.rank === 0) exp = `(${this.exp})*(${that.exp})`
-        else if (this.rank === 0) exp = `(${this.exp})*${that.exp}`
-        else if (that.rank === 0) exp = `${this.exp}*(${that.exp})`
-        else exp = `${this.exp}*${that.exp}`
-        return new Operation(this.val * that.val, 1, exp)
-    }
+    const eps = 0.000001
 
-    div(that) {
-        let exp
-        if (this.rank === 0 && that.rank !== 2) exp = `(${this.exp})/(${that.exp})`
-        else if (this.rank === 0) exp = `(${this.exp})/${that.exp}`
-        else if (that.rank !== 2) exp = `${this.exp}/(${that.exp})`
-        else exp = `${this.exp}/${that.exp}`
-        return new Operation(this.val / that.val, 1, exp)
-    }
-}
+    function dfs(nums) {
+        if (nums.length === 1 && Math.abs(nums[0].val - 24.0) < eps) return nums[0].exp
+        for (let i = 0; i < nums.length - 1; i++) {
+            for (let j = i + 1; j < nums.length; j++) {
+                let next = new Array(nums.length - 2)
+                for (let k = 0, idx = 0; k < nums.length; k++) {
+                    if (k == i || k == j) continue
+                    next[idx++] = nums[k]
+                }
+                let p = nums[i], q = nums[j]
+                let tmp = [p.plus(q), p.minus(q), q.minus(p), p.mult(q)]
+                if (q.val > 0) tmp.push(p.div(q))
+                if (p.val > 0) tmp.push(q.div(p))
+                for (let i = 0; i < tmp.length; i++) {
+                    next.push(tmp[i])
+                    const res = dfs(next)
+                    if (res !== null) return res
+                    next.pop()
+                }
+            }
+        }
+        return null
+    }    
 
-function solve24point(...numbers) {
     const nums = new Array(numbers.length)
     for (let i = 0; i < numbers.length; i++) {
         nums[i] = new Operation(numbers[i], 2, numbers[i])
@@ -45,29 +69,6 @@ function solve24point(...numbers) {
     return dfs(nums)
 }
 
-function dfs(nums) {
-    if (nums.length === 1 && Math.abs(nums[0].val - 24.0) < eps) return nums[0].exp
-    for (let i = 0; i < nums.length - 1; i++) {
-        for (let j = i + 1; j < nums.length; j++) {
-            let next = new Array(nums.length - 2)
-            for (let k = 0, idx = 0; k < nums.length; k++) {
-                if (k == i || k == j) continue
-                next[idx++] = nums[k]
-            }
-            let p = nums[i], q = nums[j]
-            let tmp = [p.plus(q), p.minus(q), q.minus(p), p.mult(q)]
-            if (q.val > 0) tmp.push(p.div(q))
-            if (p.val > 0) tmp.push(q.div(p))
-            for (let i = 0; i < tmp.length; i++) {
-                next.push(tmp[i])
-                const res = dfs(next)
-                if (res !== null) return res
-                next.pop()
-            }
-        }
-    }
-    return null
-}
 
 // eslint-disable-next-line no-console
 const log = console.log.bind(console)