Building Block
Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 32768/32768 K (Java/Others)
Total Submission(s): 3352 Accepted Submission(s): 1003
Problem Description
John are playing with blocks. There are N blocks (1 <= N <= 30000) numbered 1...N。Initially, there are N piles, and each pile contains one block. Then John do some operations P times (1 <= P <= 1000000). There are two kinds of operation:
M X Y : Put the whole pile containing block X up to the pile containing Y. If X and Y are in the same pile, just ignore this command.
C X : Count the number of blocks under block X
You are request to find out the output for each C operation.
Input
The first line contains integer P. Then P lines follow, each of which contain an operation describe above.
Output
Output the count for each C operations in one line.
Sample Input
6
M 1 6
C 1
M 2 4
M 2 6
C 3
C 4
Sample Output
1
0
2
Source
2009 Multi-University Training Contest 1 - Host by TJU
#include<iostream> #include<cstdio> #include<cstring> #include<string> #include<cmath> #include<cstdlib> #include<algorithm> using namespace std; #define maxn 300100 int n,fa[maxn],num[maxn],under[maxn]; char s[5]; int find(int x) { if(x==fa[x]) return x; int k=fa[x]; fa[x]=find(fa[x]); under[x]+=under[k]; return fa[x]; } void Union(int x,int y) { int fx,fy; fx=find(x),fy=find(y); if(fx!=fy) { under[fx]=num[fy]; num[fy]+=num[fx]; fa[fx]=fy; } } int main() { int x,y; while(scanf("%d",&n)!=EOF) { for(int i=0;i<=n;i++) fa[i]=i,num[i]=1,under[i]=0; for(int i=0;i<n;i++) { scanf("%s",s); if(s[0]==‘M‘) { scanf("%d%d",&x,&y); Union(x,y); } else if(s[0]==‘C‘) { scanf("%d",&x); find(x); printf("%d\n",under[x]); } } } return 0; }