docs: 添加仓库地址到README；chore: 整理实验分析；feat: Kruskal最小生成树与图存储结构

exercise/1.c

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+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <ctype.h>
+#ifdef _WIN32
+#include <windows.h>
+#include <direct.h>
+#endif
+
+#define MAX_SIZE 1000
+
+// 栈结构用于存储数字
+typedef struct
+{
+    int data[MAX_SIZE];
+    int top;
+} Stack;
+
+// 初始化栈
+void initStack(Stack *s)
+{
+    s->top = -1;
+}
+
+// 判断栈是否为空
+int isEmpty(Stack *s)
+{
+    return s->top == -1;
+}
+
+// 入栈
+void push(Stack *s, int value)
+{
+    if (s->top < MAX_SIZE - 1)
+    {
+        s->data[++s->top] = value;
+    }
+}
+
+// 出栈
+int pop(Stack *s)
+{
+    if (!isEmpty(s))
+    {
+        return s->data[s->top--];
+    }
+    return 0;
+}
+
+// 获取栈顶元素
+int peek(Stack *s)
+{
+    if (!isEmpty(s))
+    {
+        return s->data[s->top];
+    }
+    return 0;
+}
+
+// 判断运算符优先级
+int precedence(char op)
+{
+    if (op == '+' || op == '-')
+        return 1;
+    if (op == '*' || op == '/')
+        return 2;
+    return 0;
+}
+
+// 执行运算
+int calculate(int a, int b, char op)
+{
+    switch (op)
+    {
+    case '+':
+        return a + b;
+    case '-':
+        return a - b;
+    case '*':
+        return a * b;
+    case '/':
+        return a / b;
+    default:
+        return 0;
+    }
+}
+
+// 计算表达式
+int evaluateExpression(char *expression)
+{
+    Stack numbers;
+    Stack operators;
+    initStack(&numbers);
+    initStack(&operators);
+
+    int len = strlen(expression);
+
+    for (int i = 0; i < len; i++)
+    {
+        // 跳过空格
+        if (expression[i] == ' ')
+        {
+            continue;
+        }
+
+        // 如果是数字
+        if (isdigit(expression[i]))
+        {
+            int num = 0;
+            // 读取完整的数字
+            while (i < len && isdigit(expression[i]))
+            {
+                num = num * 10 + (expression[i] - '0');
+                i++;
+            }
+            i--; // 回退一位，因为for循环会自动增加
+            push(&numbers, num);
+        }
+        // 如果是运算符
+        else if (expression[i] == '+' || expression[i] == '-' ||
+                 expression[i] == '*' || expression[i] == '/')
+        {
+
+            // 处理运算符优先级
+            while (!isEmpty(&operators) &&
+                   precedence((char)peek(&operators)) >= precedence(expression[i]))
+            {
+                int b = pop(&numbers);
+                int a = pop(&numbers);
+                char op = (char)pop(&operators);
+                push(&numbers, calculate(a, b, op));
+            }
+            push(&operators, expression[i]);
+        }
+    }
+
+    // 处理剩余的运算符
+    while (!isEmpty(&operators))
+    {
+        int b = pop(&numbers);
+        int a = pop(&numbers);
+        char op = (char)pop(&operators);
+        push(&numbers, calculate(a, b, op));
+    }
+
+    return pop(&numbers);
+}
+
+int main()
+{
+    // 设置控制台编码为UTF-8,防止中文乱码
+#ifdef _WIN32
+    system("chcp 65001 > nul"); // 设置控制台编码为UTF-8
+    SetConsoleOutputCP(65001);  // 设置控制台输出编码
+    SetConsoleCP(65001);        // 设置控制台输入编码
+    _mkdir("records");
+#endif
+
+    char expression[MAX_SIZE];
+
+    // 读取表达式
+    if (fgets(expression, sizeof(expression), stdin) != NULL)
+    {
+        // 去除换行符
+        int len = strlen(expression);
+        if (len > 0 && expression[len - 1] == '\n')
+        {
+            expression[len - 1] = '\0';
+        }
+
+        // 计算并输出结果
+        int result = evaluateExpression(expression);
+        printf("%d\n", result);
+    }
+
+    return 0;
+}