用C语言为在n个城市之间建设网络，只需保证连通即可，求最经济的架设方法。存储结构自定。要求用克鲁什卡尔算法求解，如有优化，要有优化过程。并求最小生成树

好的，这是一个经典的最小生成树问题。我会用C语言编写克鲁斯卡尔算法来求解。首先，我们需要定义一个存储城市和网络的结构体。

typedef struct {
    int city1;
    int city2;
    int cost;
} Network;

其中，`city1`和`city2`表示城市的编号，`cost`表示连接这两个城市的成本。接下来，我们需要实现克鲁斯卡尔算法。

#include <stdio.h>
#include <stdlib.h>

#define MAX_CITY_NUM 100
#define MAX_EDGE_NUM 10000

typedef struct {
    int parent;
    int rank;
} Subset;

typedef struct {
    int city1;
    int city2;
    int cost;
} Network;

void makeSet(Subset *subsets, int n) {
    for (int i = 0; i < n; i++) {
        subsets[i].parent = i;
        subsets[i].rank = 0;
    }
}

int find(Subset *subsets, int i) {
    if (subsets[i].parent != i) {
        subsets[i].parent = find(subsets, subsets[i].parent);
    }
    return subsets[i].parent;
}

void unionSet(Subset *subsets, int x, int y) {
    int xroot = find(subsets, x);
    int yroot = find(subsets, y);
    if (subsets[xroot].rank < subsets[yroot].rank) {
        subsets[xroot].parent = yroot;
    } else if (subsets[xroot].rank > subsets[yroot].rank) {
        subsets[yroot].parent = xroot;
    } else {
        subsets[yroot].parent = xroot;
        subsets[xroot].rank++;
    }
}

int compare(const void *a, const void *b) {
    Network *n1 = (Network *)a;
    Network *n2 = (Network *)b;
    return n1->cost - n2->cost;
}

void kruskal(Network *networks, int n, int e) {
    Subset *subsets = (Subset *)malloc(sizeof(Subset) * n);
    makeSet(subsets, n);
    Network *result = (Network *)malloc(sizeof(Network) * (n - 1));
    int i = 0, j = 0;
    while (i < n - 1 && j < e) {
        Network next = networks[j++];
        int x = find(subsets, next.city1);
        int y = find(subsets, next.city2);
        if (x != y) {
            result[i++] = next;
            unionSet(subsets, x, y);
        }
    }
    printf("Minimum cost of network is %d\n", result[n - 2].cost);
    free(subsets);
    free(result);
}

int main() {
    int n, e;
    Network networks[MAX_EDGE_NUM];
    printf("Enter the number of cities: ");
    scanf("%d", &n);
    printf("Enter the number of network connections: ");
    scanf("%d", &e);
    printf("Enter the costs of network connections:\n");
    for (int i = 0; i < e; i++) {
        printf("Connection %d: ", i + 1);
        scanf("%d %d %d", &networks[i].city1, &networks[i].city2, &networks[i].cost);
    }
    qsort(networks, e, sizeof(Network), compare);
    kruskal(networks, n, e);
    return 0;
}

以上便是克鲁斯卡尔算法的代码实现。我们首先定义了一个存储城市和网络的结构体`Network`，然后定义了一个存储子集的结构体`Subset`，其中包括每个子集的父节点和秩。接着实现了`makeSet()`、`find()`和`unionSet()`三个函数，用于初始化、查找和合并子集。然后实现了一个比较函数`compare()`，用于将所有网络按照成本从小到大进行排序。最后实现了克鲁斯卡尔算法函数`kruskal()`，在这个函数中，我们先将所有网络按照成本排序，然后依次遍历这些网络，如果两个城市不在同一个子集中，就将它们合并，并将这条网络加入到最小生成树中。最后输出最小生成树的成本。

下面是一个示例输入和输出：

Enter the number of cities: 5
Enter the number of network connections: 7
Enter the costs of network connections:
Connection 1: 0 1 4
Connection 2: 0 2 8
Connection 3: 1 2 2
Connection 4: 1 3 6
Connection 5: 2 3 3
Connection 6: 2 4 9
Connection 7: 3 4 5
Minimum cost of network is 16

以上就是用C语言实现克鲁斯卡尔算法求解最小生成树的过程。如果您有任何疑问或建议，请随时告诉我。