Cube Stacking
Cube Stacking
| Time Limit: 2000MS | Memory Limit: 30000K | |
| Case Time Limit: 1000MS | ||
Description
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.
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.
* 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
6 M 1 6 C 1 M 2 4 M 2 6 C 3 C 4
Sample Output
1 0 2
分析：题意是支持2种操作，1是把包含x的联通块移到y上，2是询问x下面有几个物品；
带权并查集，p[x]为x的根，cnt[x]为x联通块大小，ret[x]为答案；
merge(i,j)时，先找到根x，y,p[x]=y，表示x移到y，ret[x]+=cnt[y],更新x答案，同时注意更新cnt[y]+=cnt[x]；
剩下路径压缩即可；
代码：
#include <iostream> #include <cstdio> #include <cstdlib> #include <cmath> #include <algorithm> #include <climits> #include <cstring> #include <string> #include <set> #include <bitset> #include <map> #include <queue> #include <stack> #include <vector> #define rep(i,m,n) for(i=m;i<=n;i++) #define mod 1000000007 #define inf 0x3f3f3f3f #define vi vector<int> #define pb push_back #define mp make_pair #define fi first #define se second #define ll long long #define pi acos(-1.0) #define pii pair<int,int> #define sys system("pause") const int maxn=1e5+10; const int N=5e4+10; const int M=N*10*10; using namespace std; inline ll gcd(ll p,ll q){return q==0?p:gcd(q,p%q);} inline ll qpow(ll p,ll q){ll f=1;while(q){if(q&1)f=f*p;p=p*p;q>>=1;}return f;} inline void umax(ll &p,ll q){if(p<q)p=q;} inline void umin(ll &p,ll q){if(p>q)p=q;} int n,m,k,t,p[maxn],ret[maxn],cnt[maxn]; char op[2]; int find(int x) { if(x==p[x])return x; int y=p[x]; p[x]=find(p[x]); ret[x]+=ret[y]; return p[x]; } int main() { int i,j; scanf("%d",&n); rep(i,1,n)p[i]=i,cnt[i]=1; rep(i,1,n) { scanf("%s%d",op,&j); if(op[0]=='M') { scanf("%d",&k); int x=find(j),y=find(k); p[x]=y; ret[x]+=cnt[y]; cnt[y]+=cnt[x]; } else { find(j); printf("%d\n",ret[j]); } } return 0; }
