Reimplement the graph code for C

codes/c/chapter_graph/graph_adjacency_matrix.c

@@ -6,24 +6,75 @@
 
 #include "../utils/common.h"
 
-/* 基于邻接矩阵实现的无向图类结构 */
+// 假设顶点数量最大为 100
+#define MAX_SIZE 100
+
+/* 基于邻接矩阵实现的无向图结构体 */
 typedef struct {
-    int *vertices; // 顶点列表
-    int **adjMat;  // 邻接矩阵，元素代表“边”，索引代表“顶点索引”
-    int size;      // 顶点数量
-    int capacity;  // 图容量
+    int vertices[MAX_SIZE];
+    int adjMat[MAX_SIZE][MAX_SIZE];
+    int size;
 } GraphAdjMat;
 
+/* 构造函数 */
+GraphAdjMat *newGraphAdjMat() {
+    GraphAdjMat *graph = (GraphAdjMat *)malloc(sizeof(GraphAdjMat));
+    graph->size = 0;
+    for (int i = 0; i < MAX_SIZE; i++) {
+        for (int j = 0; j < MAX_SIZE; j++) {
+            graph->adjMat[i][j] = 0;
+        }
+    }
+    return graph;
+}
+
+/* 添加顶点 */
+void addVertex(GraphAdjMat *graph, int val) {
+    if (graph->size == MAX_SIZE) {
+        fprintf(stderr, "图的顶点数量已达最大值\n");
+        return;
+    }
+    // 添加第 n 个顶点，并将第 n 行和列置零
+    int n = graph->size;
+    graph->vertices[n] = val;
+    for (int i = 0; i <= n; i++) {
+        graph->adjMat[n][i] = graph->adjMat[i][n] = 0;
+    }
+    graph->size++;
+}
+
+/* 删除顶点 */
+void removeVertex(GraphAdjMat *graph, int index) {
+    if (index < 0 || index >= graph->size) {
+        fprintf(stderr, "顶点索引越界\n");
+        return;
+    }
+    // 在顶点列表中移除索引 index 的顶点
+    for (int i = index; i < graph->size - 1; i++) {
+        graph->vertices[i] = graph->vertices[i + 1];
+    }
+    // 在邻接矩阵中删除索引 index 的行
+    for (int i = index; i < graph->size - 1; i++) {
+        for (int j = 0; j < graph->size; j++) {
+            graph->adjMat[i][j] = graph->adjMat[i + 1][j];
+        }
+    }
+    // 在邻接矩阵中删除索引 index 的列
+    for (int i = 0; i < graph->size; i++) {
+        for (int j = index; j < graph->size - 1; j++) {
+            graph->adjMat[i][j] = graph->adjMat[i][j + 1];
+        }
+    }
+    graph->size--;
+}
+
 /* 添加边 */
 // 参数 i, j 对应 vertices 元素索引
 void addEdge(GraphAdjMat *graph, int i, int j) {
-    // 越界检查
     if (i < 0 || j < 0 || i >= graph->size || j >= graph->size || i == j) {
-        printf("Out of range in %s:%d\n", __FILE__, __LINE__);
-        exit(1);
+        fprintf(stderr, "边索引越界或相等\n");
+        return;
     }
-    // 添加边
-    // 参数 i, j 对应 vertices 元素索引
     graph->adjMat[i][j] = 1;
     graph->adjMat[j][i] = 1;
 }
@@ -31,186 +82,64 @@ void addEdge(GraphAdjMat *graph, int i, int j) {
 /* 删除边 */
 // 参数 i, j 对应 vertices 元素索引
 void removeEdge(GraphAdjMat *graph, int i, int j) {
-    // 越界检查
     if (i < 0 || j < 0 || i >= graph->size || j >= graph->size || i == j) {
-        printf("Out of range in %s:%d\n", __FILE__, __LINE__);
-        exit(1);
+        fprintf(stderr, "边索引越界或相等\n");
+        return;
     }
-    // 删除边
-    // 参数 i, j 对应 vertices 元素索引
     graph->adjMat[i][j] = 0;
     graph->adjMat[j][i] = 0;
 }
 
-/* 添加顶点 */
-void addVertex(GraphAdjMat *graph, int val) {
-    // 如果实际使用不大于预设空间，则直接初始化新空间
-    if (graph->size < graph->capacity) {
-        graph->vertices[graph->size] = val; // 初始化新顶点值
-        for (int i = 0; i < graph->size; i++) {
-            graph->adjMat[i][graph->size] = 0; // 邻接矩新列阵置0
-        }
-        memset(graph->adjMat[graph->size], 0, sizeof(int) * (graph->size + 1)); // 将新增行置 0
-        graph->size++;
-        return;
-    }
-    // 扩容，申请新的顶点数组
-    int *temp = (int *)malloc(sizeof(int) * (graph->size * 2));
-    memcpy(temp, graph->vertices, sizeof(int) * graph->size);
-    temp[graph->size] = val;
-    // 释放原数组
-    free(graph->vertices);
-    graph->vertices = temp;
-    // 扩容，申请新的二维数组
-    int **tempMat = (int **)malloc(sizeof(int *) * graph->size * 2);
-    int *tempMatLine = (int *)malloc(sizeof(int) * (graph->size * 2) * (graph->size * 2));
-    memset(tempMatLine, 0, sizeof(int) * (graph->size * 2) * (graph->size * 2));
-    for (int k = 0; k < graph->size * 2; k++) {
-        tempMat[k] = tempMatLine + k * (graph->size * 2);
-    }
+/* 打印邻接矩阵 */
+void printGraphAdjMat(GraphAdjMat *graph) {
+    printf("顶点列表 = ");
+    printArray(graph->vertices, graph->size);
+    printf("邻接矩阵 =\n");
     for (int i = 0; i < graph->size; i++) {
-        memcpy(tempMat[i], graph->adjMat[i], sizeof(int) * graph->size); // 原数据复制到新数组
+        printArray(graph->adjMat[i], graph->size);
     }
-    for (int i = 0; i < graph->size; i++) {
-        tempMat[i][graph->size] = 0; // 将新增列置 0
-    }
-    memset(tempMat[graph->size], 0, sizeof(int) * (graph->size + 1)); // 将新增行置 0
-    // 释放原数组
-    free(graph->adjMat[0]);
-    free(graph->adjMat);
-    // 扩容后，指向新地址
-    graph->adjMat = tempMat; // 指向新的邻接矩阵地址
-    graph->capacity = graph->size * 2;
-    graph->size++;
-}
-
-/* 删除顶点 */
-void removeVertex(GraphAdjMat *graph, int index) {
-    // 越界检查
-    if (index < 0 || index >= graph->size) {
-        printf("Out of range in %s:%d\n", __FILE__, __LINE__);
-        exit(1);
-    }
-    for (int i = index; i < graph->size - 1; i++) {
-        graph->vertices[i] = graph->vertices[i + 1]; // 清除删除的顶点，并将其后所有顶点前移
-    }
-    graph->vertices[graph->size - 1] = 0; // 将被前移的最后一个顶点置 0
-    // 清除邻接矩阵中删除的列
-    for (int i = 0; i < graph->size - 1; i++) {
-        if (i < index) {
-            for (int j = index; j < graph->size - 1; j++) {
-                graph->adjMat[i][j] = graph->adjMat[i][j + 1]; // 被删除列后的所有列前移
-            }
-        } else {
-            memcpy(graph->adjMat[i], graph->adjMat[i + 1], sizeof(int) * graph->size); // 被删除行的下方所有行上移
-            for (int j = index; j < graph->size; j++) {
-                graph->adjMat[i][j] = graph->adjMat[i][j + 1]; // 被删除列后的所有列前移
-            }
-        }
-    }
-    graph->size--;
-}
-
-/* 打印顶点与邻接矩阵 */
-void printGraph(GraphAdjMat *graph) {
-    if (graph->size == 0) {
-        printf("graph is empty\n");
-        return;
-    }
-    printf("顶点列表 = [");
-    for (int i = 0; i < graph->size; i++) {
-        if (i != graph->size - 1) {
-            printf("%d, ", graph->vertices[i]);
-        } else {
-            printf("%d", graph->vertices[i]);
-        }
-    }
-    printf("]\n");
-    printf("邻接矩阵 =\n[\n");
-    for (int i = 0; i < graph->size; i++) {
-        printf("  [");
-        for (int j = 0; j < graph->size; j++) {
-            if (j != graph->size - 1) {
-                printf("%u, ", graph->adjMat[i][j]);
-            } else {
-                printf("%u", graph->adjMat[i][j]);
-            }
-        }
-        printf("],\n");
-    }
-    printf("]\n");
-}
-
-/* 构造函数 */
-GraphAdjMat *newGraphAjdMat(int numberVertices, int *vertices, int **adjMat) {
-    // 申请内存
-    GraphAdjMat *newGraph = (GraphAdjMat *)malloc(sizeof(GraphAdjMat));    // 为图分配内存
-    newGraph->vertices = (int *)malloc(sizeof(int) * numberVertices * 2);  // 为顶点列表分配内存
-    newGraph->adjMat = (int **)malloc(sizeof(int *) * numberVertices * 2); // 为邻接矩阵分配二维内存
-    int *temp = (int *)malloc(sizeof(int) * numberVertices * 2 * numberVertices * 2); // 为邻接矩阵分配一维内存
-    newGraph->size = numberVertices;                                                  // 初始化顶点数量
-    newGraph->capacity = numberVertices * 2;                                          // 初始化图容量
-    // 配置二维数组
-    for (int i = 0; i < numberVertices * 2; i++) {
-        newGraph->adjMat[i] = temp + i * numberVertices * 2; // 将二维指针指向一维数组
-    }
-    // 赋值
-    memcpy(newGraph->vertices, vertices, sizeof(int) * numberVertices);
-    for (int i = 0; i < numberVertices; i++) {
-        memcpy(newGraph->adjMat[i], adjMat[i],
-               sizeof(int) * numberVertices); // 将传入的邻接矩阵赋值给结构体内邻接矩阵
-    }
-    // 返回结构体指针
-    return newGraph;
 }
 
 /* Driver Code */
 int main() {
-    /* 初始化无向图 */
-    int vertices[5] = {1, 3, 2, 5, 4};
-    int **edge = (int **)malloc(sizeof(int *) * 5);
-    // 用于构建二维数组的一维指针
-    int *temp = (int *)malloc(sizeof(int) * 25);
-    memset(temp, 0, sizeof(int) * 25);
-    for (int k = 0; k < 5; k++) {
-        edge[k] = temp + k * 5;
+    // 初始化无向图
+    GraphAdjMat *graph = newGraphAdjMat();
+    int vertices[] = {1, 3, 2, 5, 4};
+    for (int i = 0; i < 5; i++) {
+        addVertex(graph, vertices[i]);
     }
-    // 初始化边
-    edge[0][1] = edge[1][0] = 1;
-    edge[0][3] = edge[3][0] = 1;
-    edge[1][2] = edge[2][1] = 1;
-    edge[2][3] = edge[3][2] = 1;
-    edge[2][4] = edge[4][2] = 1;
-    edge[3][4] = edge[4][3] = 1;
-    // 建立无向图
-    GraphAdjMat *graph = newGraphAjdMat(5, vertices, edge);
-    free(edge);
-    free(temp);
-    printf("\n初始化后，图为:\n");
-    printGraph(graph);
+    int edges[][2] = {{0, 1}, {0, 3}, {1, 2}, {2, 3}, {2, 4}, {3, 4}};
+    for (int i = 0; i < 6; i++) {
+        addEdge(graph, edges[i][0], edges[i][1]);
+    }
+    printf("\n初始化后，图为\n");
+    printGraphAdjMat(graph);
 
     /* 添加边 */
     // 顶点 1, 2 的索引分别为 0, 2
     addEdge(graph, 0, 2);
-    printf("\n添加边 1-2 后图为\n");
-    printGraph(graph);
+    printf("\n添加边 1-2 后，图为\n");
+    printGraphAdjMat(graph);
 
     /* 删除边 */
     // 顶点 1, 3 的索引分别为 0, 1
     removeEdge(graph, 0, 1);
     printf("\n删除边 1-3 后，图为\n");
-    printGraph(graph);
+    printGraphAdjMat(graph);
 
     /* 添加顶点 */
     addVertex(graph, 6);
     printf("\n添加顶点 6 后，图为\n");
-    printGraph(graph);
+    printGraphAdjMat(graph);
 
     /* 删除顶点 */
     // 顶点 3 的索引为 1
     removeVertex(graph, 1);
     printf("\n删除顶点 3 后，图为\n");
-    printGraph(graph);
+    printGraphAdjMat(graph);
+
+    // 释放内存
+    free(graph);
 
     return 0;
 }