Add solution and test-cases for problem 241

Author: 0xff-dev

leetcode/201-300/0241.Different-Ways-to-Add-Parentheses/Solution.go

@@ -53,3 +53,96 @@ func ways(input string, cache map[string][]int) []int {
 
 return ans
 }
+
+// Solution2
+type operation struct {
+val int
+op byte
+}
+
+func calResult(a, b int, op byte) int {
+if op == '*' {
+return a * b
+}
+if op == '+' {
+return a + b
+}
+return a - b
+}
+
+func diffWaysToCompute2(expression string) []int {
+opts := make([]operation, 0)
+base := 1
+c := 0
+// 245
+for idx := len(expression) - 1; idx >= 0; idx-- {
+if expression[idx] >= '0' && expression[idx] <= '9' {
+c = base*int(expression[idx]-'0') + c
+base *= 10
+continue
+}
+opts = append(opts, operation{val: c}, operation{op: expression[idx]})
+base, c = 1, 0
+}
+opts = append(opts, operation{val: c})
+
+length := len(opts)
+if length == 1 {
+return []int{opts[0].val}
+}
+for s, e := 0, length-1; s < e; s, e = s+1, e-1 {
+opts[s], opts[e] = opts[e], opts[s]
+}
+
+ans := make([]int, 0)
+dp := make([][]map[int]int, length)
+// 需要明确dp[i][j] 能计算出多少种结果
+for i := 0; i < length; i++ {
+dp[i] = make([]map[int]int, length)
+for j := 0; j < length; j++ {
+dp[i][j] = make(map[int]int)
+}
+if i&1 == 0 {
+dp[i][i][opts[i].val] = 1
+}
+}
+
+// 2 - 1 - 1-1
+// n=2 0-2, 2-4, 4-6
+// n=3,0-4, 2-6
+// n=4,0-6
+// n = 4 end=6
+// length=7
+// 2-1
+// 2 有一个操作数，3有两个，4有3个
+// 2 = 1+0
+// 3 = 2+1
+// 4 = 3 + 2
+// length - 1 - n+1 -n+2
+
+for n := 2; n <= length/2+1; n++ {
+for start := 0; start < length+2-2*n; start += 2 {
+end := start + 2*(n-1)
+for k := start; k < end; k += 2 {
+for v1, c1 := range dp[start][k] {
+for v2, c2 := range dp[k+2][end] {
+r := calResult(v1, v2, opts[k+1].op)
+dp[start][end][r] += c1 * c2
+}
+}
+}
+}
+}
+for idx := length - 1; idx > 0; idx -= 2 {
+op := opts[idx-1].op
+for v1, c1 := range dp[idx][length-1] {
+for v2, c2 := range dp[0][idx-2] {
+r := calResult(v2, v1, op)
+for loop := c1 * c2; loop > 0; loop-- {
+ans = append(ans, r)
+}
+}
+}
+}
+return ans
+}

leetcode/201-300/0241.Different-Ways-to-Add-Parentheses/Solution_test.go

@@ -1,6 +1,7 @@
 package Solution
 
 import (
+"sort"
 "strconv"
 "testing"
 )
@@ -12,8 +13,9 @@ func TestSolution(t *testing.T) {
 inputs string
 expect []int
 }{
-{"TestCase", "2-1-1", []int{0, 2}},
-{"TestCase", "2*3-4*5", []int{-34, -14, -10, -10, 10}},
+{"TestCase1", "2-1-1", []int{0, 2}},
+{"TestCase2", "2*3-4*5", []int{-34, -14, -10, -10, 10}},
+{"TestCase3", "10+5", []int{15}},
 }
 
 //	开始测试
@@ -32,14 +34,29 @@ func TestSolution(t *testing.T) {
 t.Fatalf("expected: %v, but got: %v, with inputs: %v", c.expect, got, c.inputs)
 }
 }
+
+got = diffWaysToCompute2(c.inputs)
+sort.Ints(got)
+if len(got) != len(c.expect) {
+t.Fatalf("expected: %v, but got: %v, with inputs: %v", c.expect, got, c.inputs)
+}
+m = make(map[int]int)
+for v := range got {
+m[v]++
+}
+for v := range c.expect {
+if _, ok := m[v]; !ok {
+t.Fatalf("expected: %v, but got: %v, with inputs: %v", c.expect, got, c.inputs)
+}
+}
 })
 }
 }
 
-//压力测试
+// 压力测试
 func BenchmarkSolution(b *testing.B) {
 }
 
-//使用案列
+// 使用案列
 func ExampleSolution() {
 }