Cube Stacking
阿新 • • 發佈：2019-02-13
Farmer John and Betsy are playing a game with N (1 <= N <= 30,000)identical cubes labeled 1 through N. They start with N stacks, each containing a single cube. Farmer John asks Betsy to perform P (1<= P <= 100,000) operation. There are two types of operations:
moves and counts.
* In a move operation, Farmer John asks Bessie to move the stack containing cube X on top of the stack containing cube Y.
* In a count operation, Farmer John asks Bessie to count the number of cubes on the stack with cube X that are under the cube X and report that value.
Write a program that can verify the results of the game.
Input* Line 1: A single integer, P
* Lines 2..P+1: Each of these lines describes a legal operation. Line 2 describes the first operation, etc. Each line begins with a 'M' for a move operation or a 'C' for a count operation. For move operations, the line also contains two integers: X and Y.For count operations, the line also contains a single integer: X.
Note that the value for N does not appear in the input file. No move operation will request a move a stack onto itself.
OutputPrint the output from each of the count operations in the same order as the input file.
Sample Input
moves and counts.
* In a move operation, Farmer John asks Bessie to move the stack containing cube X on top of the stack containing cube Y.
* In a count operation, Farmer John asks Bessie to count the number of cubes on the stack with cube X that are under the cube X and report that value.
Write a program that can verify the results of the game.
Input* Line 1: A single integer, P
* Lines 2..P+1: Each of these lines describes a legal operation. Line 2 describes the first operation, etc. Each line begins with a 'M' for a move operation or a 'C' for a count operation. For move operations, the line also contains two integers: X and Y.For count operations, the line also contains a single integer: X.
Note that the value for N does not appear in the input file. No move operation will request a move a stack onto itself.
OutputPrint the output from each of the count operations in the same order as the input file.
Sample Input
6 M 1 6 C 1 M 2 4 M 2 6 C 3 C 4
1 0 2
分析：
deep[i]表示編號為i的cube距離top的cube深度是多少
num[i]表示編號為i的cube有幾個孩子結點，i本身也算。
每次join(a,b)的時候，就把a及以上的點deep算好了
程式碼如下：
#include<iostream> #include<cstdio> #include<cstring> using namespace std; const int maxn=30002; int num[maxn],deep[maxn],pre[maxn]; int f(int a){ if(pre[a]==a)return a; int tmp=pre[a]; pre[a]=f(tmp); deep[a]+=deep[tmp]; return pre[a]; } void join(int a,int b){ int root1=f(a),root2=f(b); if(root1!=root2){ pre[root2]=root1; deep[root2]=num[root1]; num[root1]+=num[root2]; } } int main(){ for(int i=1;i<=maxn;i++){ pre[i]=i; num[i]=1; deep[i]=0; } int p,a,b,x; char ch[5]; scanf("%d",&p); while(p--){ scanf("%s",&ch); if(ch[0]=='M'){ scanf("%d%d",&a,&b); join(a,b); } else { scanf("%d",&x); f(x); printf("%d\n",num[f(x)]-deep[x]-1); } } }