File Transfer-and check set
Normal thinking
struct setnode {
int data; /*data好像没啥屁用还要来一遍遍历，赶紧滚吧*/
int parent;
}set[maxsize];
int findp(setnode s[], int x) {
/*找到根结点*/
int i;
for (i = 0; i < maxsize&&s[i].data != x; i++); //严重增加时间复杂度
if (i >= maxsize) return -1;
for (; s[i].parent>=0; i = s[i].parent);
return i;
/*if (s[i].parent < 0) return x;
else return x = findp(s[],s[i].parent);*/
}
int unionset(setnode s[]) {
/*直接合并*/
int a, b;
scanf("%d %d", &a, &b);
int root1 = findp(s, a);
int root2 = findp(s, b);
if (root1 != root2) s[root1].parent = root2;
return true;
}
Improve
int supers[maxsize]; //s[i]，把数据对i做一个映射，i是递增数据的编号，s[i]同时代表parent
int findnum(int s[], int x) {
if (s[x] < 0) return x;
else return s[x] = findnum(s, s[x]); //用递归将所有子结点连接到根结点上，压缩路径
}
int superunion(int s[]) {
//比较两个树的树高或者节点数，小树贴在大树上，按秩归并
int a, b;
scanf("%d %d", &a, &b);
int root1 = findnum(s, a); //结合使用压缩路径，因此树高都是2，s[root]设为节点数比较好
int root2 = findnum(s, b);
if (s[root1] > s[root2]) {
s[root2] += s[root1];
s[root1] = root2;
}
else {
s[root1] += s[root2];
s[root2] = root1;
}
return true;
}
int check(int s[]) {
/*是否联通*/
int a, b;
scanf("%d %d", &a, &b);
int root1 = findnum(s, a);
int root2 = findnum(s, b);
if (root1 == root2) printf("yes\n");
else printf("no\n");
return true;
}
void checkset(int s[],int n) {
/*有几个连通集*/
int i, count;
count = 0;
for (i = 0; i < n; i++) {
if (s[i] < 0) count++;
}
if (count == 1) printf("The network is connected.");
else printf("There are %d components.", count);
}
int main() {
int n;
scanf("%d", &n);
for (int i = 0; i < n; i++) /*初始化*/
supers[i] = -1;
char choice;
do{
scanf("%c", &choice);
switch (choice)
{
case 'I':
superunion(supers);
break;
case 'C':
check(supers);
break;
case 'S':
checkset(supers,n);
break;
default:
break;
}
} while (choice != 'S');
return 0;
}