HOJ 2385 Cube Stacking

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.

Output

Print the output from each of the count operations in the same order as the input file.

Sample Input

6M 1 6C 1M 2 4M 2 6C 3C 4

Sample Output

102

题解：

                并查集，并记录i元素上面和下面的元素个数

#include <cstdio>#include <cstdlib>#include <cstring>const int N = 30005;int set[N];int high[N]; //i元素上面（加上i）的元素个数 int low[N];  //i元素下面的元素个数 int findset(int x){if(x == set[x])return set[x];int tm = set[x];set[x] = findset(set[x]);low[x] += low[tm];return set[x];}void unionset(int x,int y){int fx = findset(x);int fy = findset(y);if( fx == fy)return ;set[fx] = fy;low[fx] += high[fy];high[fy] += high[fx];}int main(){int n;while(scanf("%d",&n) != EOF){for(int i = 1; i <= N; i++){set[i] = i;         high[i] = 1;}memset(low,0,sizeof(low));char op;int x,y;getchar();for(int i =1 ; i <= n; i++){scanf("%c",&op);if(op == 'C'){scanf("%d",&x);findset(x);printf("%d\n",low[x]);}else{scanf("%d%d",&x,&y);unionset(x,y);}getchar();}}return 0;}