From 934b56779831bcbfe84fb0c7162a021916b5275d Mon Sep 17 00:00:00 2001
From: knowledgaction <1113798773@qq.com>
Date: Mon, 10 Jul 2023 15:37:49 +0800
Subject: [PATCH 1/2] Update main.cpp
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hw3，磕磕绊绊，不太熟练地完成了
---
 main.cpp | 39 ++++++++++++++++++++++++++++++++++++---
 1 file changed, 36 insertions(+), 3 deletions(-)

diff --git a/main.cpp b/main.cpp
index d76cce7..32b77e7 100644
--- a/main.cpp
+++ b/main.cpp
@@ -3,6 +3,7 @@
 #include <variant>
 
 // 请修复这个函数的定义：10 分
+template<class T>
 std::ostream &operator<<(std::ostream &os, std::vector<T> const &a) {
     os << "{";
     for (size_t i = 0; i < a.size(); i++) {
@@ -15,20 +16,49 @@ std::ostream &operator<<(std::ostream &os, std::vector<T> const &a) {
 }
 
 // 请修复这个函数的定义：10 分
-template <class T1, class T2>
-std::vector<T0> operator+(std::vector<T1> const &a, std::vector<T2> const &b) {
+template <class T1, class T2>   // 第一个加法，  vector相加
+std::vector<std::common_type_t<T1,T2>> operator+(std::vector<T1> const &a, std::vector<T2> const &b) {
     // 请实现列表的逐元素加法！10 分
     // 例如 {1, 2} + {3, 4} = {4, 6}
+    std::vector<std::common_type_t<T1,T2>> sum;
+    size_t N = std::min(a.size(), b.size());
+    for (size_t i=0;i<N;i++){
+        sum.push_back(a[i] + b[i]);
+    }
+    return sum;
 }
 
-template <class T1, class T2>
+template <class T1, class T2>   // 第二个加法，   variant+variant
 std::variant<T1, T2> operator+(std::variant<T1, T2> const &a, std::variant<T1, T2> const &b) {
     // 请实现自动匹配容器中具体类型的加法！10 分
+
+    return std::visit([&](const auto& i, const auto& j)->std::variant<T1, T2> {return i + j;}, a, b);
+}
+
+template <class T1, class T2>   // 第二个加法，   variant+vector
+std::variant<T1, T2> operator+(std::variant<T1, T2> const &a, T2 const &b) {
+    // 请实现自动匹配容器中具体类型的加法！10 分
+
+    return a + std::variant<T1, T2>{b};
+}
+
+template <class T1, class T2>   // 第二个加法，   vector+variant
+std::variant<T1, T2> operator+(T1  const &a, std::variant<T1, T2> const &b) {
+    // 请实现自动匹配容器中具体类型的加法！10 分
+    return b + std::variant<T1, T2>{a};
 }
 
 template <class T1, class T2>
 std::ostream &operator<<(std::ostream &os, std::variant<T1, T2> const &a) {
     // 请实现自动匹配容器中具体类型的打印！10 分
+    std::visit([&](const auto& i){std::cout << i << std::endl;}, a);
+    return os;
+}
+
+template <class T1,class... Targs>
+std::ostream &operator<<(std::ostream &os, std::variant<T1,Targs...> const &args){
+    std::visit([&](const auto& i){std::cout << i << std::endl;}, args);
+    return os;
 }
 
 int main() {
@@ -51,5 +81,8 @@ int main() {
     // 应该输出 {9.28, 17.436, 7.236}
     std::cout << d << std::endl;
 
+    std::variant<int, double, std::vector<int>> temp{666};
+    std::cout << temp << std::endl;
+
     return 0;
 }

From 301c9a44675205cc5e0cdd0f08a85d1f818c04b6 Mon Sep 17 00:00:00 2001
From: knowledgaction <1113798773@qq.com>
Date: Mon, 10 Jul 2023 16:32:36 +0800
Subject: [PATCH 2/2] Update main.cpp

---
 main.cpp | 9 +--------
 1 file changed, 1 insertion(+), 8 deletions(-)

diff --git a/main.cpp b/main.cpp
index 32b77e7..c6e9b4d 100644
--- a/main.cpp
+++ b/main.cpp
@@ -48,13 +48,6 @@ std::variant<T1, T2> operator+(T1  const &a, std::variant<T1, T2> const &b) {
     return b + std::variant<T1, T2>{a};
 }
 
-template <class T1, class T2>
-std::ostream &operator<<(std::ostream &os, std::variant<T1, T2> const &a) {
-    // 请实现自动匹配容器中具体类型的打印！10 分
-    std::visit([&](const auto& i){std::cout << i << std::endl;}, a);
-    return os;
-}
-
 template <class T1,class... Targs>
 std::ostream &operator<<(std::ostream &os, std::variant<T1,Targs...> const &args){
     std::visit([&](const auto& i){std::cout << i << std::endl;}, args);
@@ -81,7 +74,7 @@ int main() {
     // 应该输出 {9.28, 17.436, 7.236}
     std::cout << d << std::endl;
 
-    std::variant<int, double, std::vector<int>> temp{666};
+    std::variant<int> temp{666};
     std::cout << temp << std::endl;
 
     return 0;