From afdacc3965a87f2e6fb9515302fba8e8a8e7eb9e Mon Sep 17 00:00:00 2001
From: tiennm99 <tiennm99@outlook.com>
Date: Mon, 8 Dec 2025 12:33:57 +0700
Subject: [PATCH] Create voiexam.go

---
 go/voiexam.go | 152 ++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 152 insertions(+)
 create mode 100644 go/voiexam.go

diff --git a/go/voiexam.go b/go/voiexam.go
new file mode 100644
index 0000000..fb79cd6
--- /dev/null
+++ b/go/voiexam.go
@@ -0,0 +1,152 @@
+package main
+
+import (
+	"bufio"
+	"fmt"
+	"os"
+	"sort"
+	"strconv"
+)
+
+type Pair struct {
+	val int64
+	str string
+}
+
+func calc(a int64, op byte, b int64) int64 {
+	if op == '+' {
+		return a + b
+	}
+	if op == '-' {
+		return a - b
+	}
+	return a * b
+}
+
+func ts(x int64) string {
+	return strconv.FormatInt(x, 10)
+}
+
+func getAll(nums []int64, ops []byte) []Pair {
+	sz := len(nums)
+	var result []Pair
+	seen := make(map[int64]bool)
+
+	if sz == 2 {
+		v := calc(nums[0], ops[0], nums[1])
+		result = append(result, Pair{v, ts(nums[0]) + string(ops[0]) + ts(nums[1])})
+	} else if sz == 3 {
+		a, b, c := nums[0], nums[1], nums[2]
+		o1, o2 := ops[0], ops[1]
+		v1 := calc(a, o1, calc(b, o2, c))
+		v2 := calc(calc(a, o1, b), o2, c)
+		s1 := ts(a) + string(o1) + "(" + ts(b) + string(o2) + ts(c) + ")"
+		s2 := "(" + ts(a) + string(o1) + ts(b) + ")" + string(o2) + ts(c)
+		result = append(result, Pair{v1, s1})
+		seen[v1] = true
+		if !seen[v2] {
+			seen[v2] = true
+			result = append(result, Pair{v2, s2})
+		}
+	} else {
+		a, b, c, d := nums[0], nums[1], nums[2], nums[3]
+		o1, o2, o3 := ops[0], ops[1], ops[2]
+		all := []Pair{
+			{calc(a, o1, calc(b, o2, calc(c, o3, d))), ts(a) + string(o1) + "(" + ts(b) + string(o2) + "(" + ts(c) + string(o3) + ts(d) + "))"},
+			{calc(a, o1, calc(calc(b, o2, c), o3, d)), ts(a) + string(o1) + "((" + ts(b) + string(o2) + ts(c) + ")" + string(o3) + ts(d) + ")"},
+			{calc(calc(a, o1, b), o2, calc(c, o3, d)), "(" + ts(a) + string(o1) + ts(b) + ")" + string(o2) + "(" + ts(c) + string(o3) + ts(d) + ")"},
+			{calc(calc(a, o1, calc(b, o2, c)), o3, d), "(" + ts(a) + string(o1) + "(" + ts(b) + string(o2) + ts(c) + "))" + string(o3) + ts(d)},
+			{calc(calc(calc(a, o1, b), o2, c), o3, d), "((" + ts(a) + string(o1) + ts(b) + ")" + string(o2) + ts(c) + ")" + string(o3) + ts(d)},
+		}
+		for _, p := range all {
+			if !seen[p.val] {
+				seen[p.val] = true
+				result = append(result, p)
+			}
+		}
+	}
+
+	// --- FIX: Sort the results by value to ensure deterministic behavior ---
+	sort.Slice(result, func(i, j int) bool {
+		if result[i].val != result[j].val {
+			return result[i].val < result[j].val
+		}
+		// As a tie-breaker for complete determinism, sort by string representation
+		return result[i].str < result[j].str
+	})
+
+	return result
+}
+
+func exam(in *os.File, out *os.File) {
+	reader := bufio.NewReader(in)
+	writer := bufio.NewWriter(out)
+	defer writer.Flush()
+
+	var n int
+	fmt.Fscan(reader, &n)
+
+	exprs := make([][]Pair, n)
+
+	for i := 0; i < n; i++ {
+		var s string
+		fmt.Fscan(reader, &s)
+		var nums []int64
+		var ops []byte
+		var num int64 = 0
+		for j := 0; j < len(s); j++ {
+			c := s[j]
+			if c >= '0' && c <= '9' {
+				num = num*10 + int64(c-'0')
+			} else {
+				nums = append(nums, num)
+				num = 0
+				ops = append(ops, c)
+			}
+		}
+		nums = append(nums, num)
+		exprs[i] = getAll(nums, ops)
+	}
+
+	order := make([]int, n)
+	for i := 0; i < n; i++ {
+		order[i] = i
+	}
+	sort.Slice(order, func(i, j int) bool {
+		return len(exprs[order[i]]) < len(exprs[order[j]])
+	})
+
+	result := make([]string, n)
+	used := make(map[int64]bool)
+
+	var solve func(idx int) bool
+	solve = func(idx int) bool {
+		if idx == n {
+			return true
+		}
+		i := order[idx]
+		for _, p := range exprs[i] {
+			if !used[p.val] {
+				used[p.val] = true
+				result[i] = p.str
+				if solve(idx + 1) {
+					return true
+				}
+				delete(used, p.val)
+			}
+		}
+		return false
+	}
+
+	if solve(0) {
+		for _, s := range result {
+			fmt.Fprintln(writer, s)
+		}
+	} else {
+		fmt.Fprintln(writer, "NO SOLUTION")
+	}
+}
+
+func main() {
+	exam(os.Stdin, os.Stdout)
+}