最小生成树Kruskal算法朴素版 C语言实现

标签：最小生成树

Prim算法
参考博客
并查集基础及练习

#include <stdio.h>#include <algorithm>using namespace std;#define maxn 20typedef struct{    int x, y;    int w;}edge;edge e[maxn];int rank_[maxn], father[maxn], sum;int cmp(edge a, edge b){  //按权值非降序排序(相同则按x坐标)    if(a.w == b.w)  return a.x < b.x;    return a.w < b.w;}void make_set(int x){    father[x] = x;    rank_[x] = 0;}int find_set(int x){    return  x != father[x] ? find_set(father[x]) : father[x];}void union_set(int x, int y, int w){    sum += w;    if(x == y)  return ;    if(rank_[x] > rank_[y])  father[y] = x;    else{        if(rank_[x] == rank_[y])  rank_[y]++;        father[x] = y;    }}int main(){    int n, x, y, i;    char cx, cy;    freopen("kruskal.txt", "r", stdin);    scanf("%d", &n);    getchar();    for(i = 0; i < n; i++){        scanf("%c%c %d", &cx, &cy, &e[i].w);        getchar();        e[i].x = cx -'A', e[i].y = cy - 'A';        make_set(i);  //0对应于A    }    sort(e, e + n, cmp);    //for(i = 0; i < n; i++)  printf("%c-%c : %d\n", e[i].x + 'A', e[i].y + 'A', e[i].w);    //printf("\n");    sum = 0;    for(i = 0; i < n; i++){        x = find_set(e[i].x), y = find_set(e[i].y);        if(x != y){            printf("%c-%c : %d\n", e[i].x + 'A', e[i].y + 'A', e[i].w);            union_set(x, y, e[i].w);        }    }    printf("total:  %d\n", sum);    return 0;}

数据文件：

实验结果：