feat(calc_lib): 优化大数加法, 只实现了整数

calc_lib/.vscode/settings.json

 {
     "files.associations": {
-        "xstring": "cpp"
+        "xstring": "cpp",
+        "algorithm": "cpp",
+        "array": "cpp",
+        "atomic": "cpp",
+        "bit": "cpp",
+        "cctype": "cpp",
+        "charconv": "cpp",
+        "chrono": "cpp",
+        "clocale": "cpp",
+        "cmath": "cpp",
+        "compare": "cpp",
+        "concepts": "cpp",
+        "condition_variable": "cpp",
+        "csignal": "cpp",
+        "cstdarg": "cpp",
+        "cstddef": "cpp",
+        "cstdint": "cpp",
+        "cstdio": "cpp",
+        "cstdlib": "cpp",
+        "cstring": "cpp",
+        "ctime": "cpp",
+        "cwchar": "cpp",
+        "exception": "cpp",
+        "format": "cpp",
+        "forward_list": "cpp",
+        "fstream": "cpp",
+        "functional": "cpp",
+        "initializer_list": "cpp",
+        "iomanip": "cpp",
+        "ios": "cpp",
+        "iosfwd": "cpp",
+        "iostream": "cpp",
+        "istream": "cpp",
+        "iterator": "cpp",
+        "limits": "cpp",
+        "list": "cpp",
+        "locale": "cpp",
+        "map": "cpp",
+        "memory": "cpp",
+        "mutex": "cpp",
+        "new": "cpp",
+        "optional": "cpp",
+        "ostream": "cpp",
+        "ratio": "cpp",
+        "set": "cpp",
+        "span": "cpp",
+        "sstream": "cpp",
+        "stdexcept": "cpp",
+        "stop_token": "cpp",
+        "streambuf": "cpp",
+        "string": "cpp",
+        "system_error": "cpp",
+        "thread": "cpp",
+        "tuple": "cpp",
+        "type_traits": "cpp",
+        "typeinfo": "cpp",
+        "unordered_map": "cpp",
+        "unordered_set": "cpp",
+        "utility": "cpp",
+        "vector": "cpp",
+        "xfacet": "cpp",
+        "xhash": "cpp",
+        "xiosbase": "cpp",
+        "xlocale": "cpp",
+        "xlocbuf": "cpp",
+        "xlocinfo": "cpp",
+        "xlocmes": "cpp",
+        "xlocmon": "cpp",
+        "xlocnum": "cpp",
+        "xloctime": "cpp",
+        "xmemory": "cpp",
+        "xstddef": "cpp",
+        "xtr1common": "cpp",
+        "xtree": "cpp",
+        "xutility": "cpp"
     }
 }
\ No newline at end of file

calc_lib/include/khl_calc/khl_calc_decimal.h

-#ifndef  _KHL_CALC_DECIMAL_H_
-#define  _KHL_CALC_DECIMAL_H_
+#ifndef _KHL_CALC_DECIMAL_H_
+#define _KHL_CALC_DECIMAL_H_
 
 #include <string>
 

calc_lib/src/khl_calc/khl_calc_decimal.cpp

 #include <iostream>
 #include <memory>
-#include <cstring>
-#include <sstream>
 #include <algorithm>
 #include "khl_calc/khl_calc_decimal.h"
 
@@ -9,56 +7,80 @@ KHL_CALC_NAMESPACE_BEGIN
 
 std::string Decimal::add(std::string x, std::string y)
 {
-    /** 入参转换为 int 数组, 并倒置 */
-    char * sx = const_cast<char *>(x.c_str());
-    char * sy = const_cast<char *>(y.c_str());
-
-    const size_t lx = strlen(sx);
-    const size_t ly = strlen(sy);
+    /**
+     * 对齐数字
+     * x = 123 , y = 4567
+     * x = 0123 , y = 4567
+     */
+    if (x.size() != y.size())
+    {
+        if (x.size() > y.size())
+        {
+            auto len = x.size() - y.size();
+            for (int i = 0; i < len; i++)
+            {
+                y.insert(0, "0");
+            }
+        }
+        else
+        {
+            auto len = y.size() - x.size();
+            for (int i = 0; i < len; i++)
+            {
+                x.insert(0, "0");
+            }
+        }
+    }
 
-    auto a = std::make_unique<int[]>(lx);
-    auto b = std::make_unique<int[]>(ly);
+    /**
+     * 对齐后的字符串转换为倒置的 int 数组
+     * x = 0123 , y = 4567
+     * x = 3210 , y = 7654
+     */
+    char *sx = const_cast<char *>(x.c_str());
+    char *sy = const_cast<char *>(y.c_str());
+    const size_t len = x.size();
+    auto a = std::make_unique<int[]>(len);
+    auto b = std::make_unique<int[]>(len);
 
-    for (int i = 0; i < lx; i++)
+    for (int i = 0; i < len; i++)
     {
-        a[lx - i] = sx[i] - '0';
+        a[len - 1 - i] = sx[i] - '0';
     }
 
-    for (int i = 0; i < ly; i++)
+    for (int i = 0; i < len; i++)
     {
-        b[ly - i] = sy[i] - '0';
+        b[len - 1 - i] = sy[i] - '0';
     }
 
     /** 计算 */
-    const size_t lc = std::max(lx, ly) + 1;
-    auto result = std::make_unique<int[]>(lc);
+    const size_t size = len + 1;
+    auto c = std::make_unique<int[]>(size);
 
-    for (int i = 0; i < lc; i++)
+    for (int i = 0; i < len; i++)
     {
-        result[i] = a[i] + b[i];
-        result[i + 1] = result[i] / 10;
-        result[i] = result[i] % 10;
+        c[i] += a[i] + b[i];
+        // 处理进位
+        if (c[i] >= 10)
+        {
+            c[i + 1] += c[i] / 10;
+            c[i] = c[i] % 10;
+        }
     }
 
-    /** 删除前导0 */
-    size_t len = lc;
-    if (0 == result[lc] && lc > 0)
+    /** 翻转计算结果 */
+    std::string str;
+    int i = size - 1;
+    if(0 == c[i])
     {
-        len--;
+        i--;
     }
-
-    /** 翻转倒置的计算结果 */
-    auto c = std::make_unique<char[]>(lc);
-    for (int i = len, j = 0; i > 0; i--, j++)
+    while( i >= 0 )    
     {
-        c[j] = result[i] + '0';
+        str.push_back(c[i] + '0');
+        i--;
     }
 
-    std::string str;
-    std::stringstream ss;
-    ss << c;
-    ss >> str;
-
     return str;
 }
 

calc_lib/src/main/main.cpp

@@ -4,9 +4,11 @@
 
 int main()
 {
-    std::cout << "hello khl_calc" << std::endl;
     auto decimal = std::make_unique<khl::calc::Decimal>();
-    std::string str = decimal->add("1","2");
-    std::cout << "result: " << str << std::endl;
+    for (int i = 0; i < 10; i++)
+    {
+        std::cout << decimal->add("465465465464", "1321654876135138468135135") << std::endl;
+        std::cout << "===================" << std::endl;
+    }
     return 0;
 }
\ No newline at end of file

calc_lib/test/testmain.cpp

@@ -10,18 +10,19 @@
 
 #include "khl_calc/khl_calc.h"
 
-TEST_CASE("test_001")
+TEST_CASE("test_add")
 {
-    spdlog::info("test 001");
+    spdlog::info("test add");
     auto decimal = std::make_unique<khl::calc::Decimal>();
-    std::string str = decimal->add("84964651354684615354684","498461351384864651684");
-    std::cout << "result: " << str << std::endl;
+    for (int i = 0; i < 10; i++)
+    {
+        std::cout << decimal->add("465465465464", "1321654876135138468135135") << std::endl;
+        std::cout << "===================" << std::endl;
+    }
+    
+    
+    // std::cout << decimal->add("1", "12") << std::endl;
+    // std::cout << decimal->add("1", "10") << std::endl;
+    // std::cout << decimal->add("12", "1") << std::endl;
+    // std::cout << decimal->add("10", "1") << std::endl;
 }
-
-TEST_CASE("test_002")
-{
-    char a = '9';
-    int b = a - '0';
-    std::cout << b << std::endl;
-}
-