During the War of Resistance Against Japan, tunnel warfare was carried out extensively in the vast areas of north China Plain. Generally speaking, villages connected by tunnels lay in a line. Except the two at the ends, every village was directly connected with two neighboring ones.
Frequently the invaders launched attack on some of the villages and destroyed the parts of tunnels in them. The Eighth Route Army commanders requested the latest connection state of the tunnels and villages. If some villages are severely isolated, restoration of connection must be done immediately!
Input The first line of the input contains two positive integers n and m (n, m ≤ 50,000) indicating the number of villages and events. Each of the next m lines describes an event.
There are three different events described in different format shown below:
D x: The x-th village was destroyed. Q x: The Army commands requested the number of villages that x-th village was directly or indirectly connected with including itself. R: The village destroyed last was rebuilt. Output Output the answer to each of the Army commanders’ request in order on a separate line.
Sample Input 7 9 D 3 D 6 D 5 Q 4 Q 5 R Q 4 R Q 4 Sample Output 1 0 2 4 Hint An illustration of the sample input:
OOOOOOOD 3 OOXOOOO
D 6 OOXOOXO
D 5 OOXOXXO
R OOXOOXO
R OOXOOOO
查詢每個點的連通數即與他相連的O的數量+1,只需要找到其往左第一個X和往右第一個X,然后求差值-1,注意邊界。用set處理很方便。
#include<iostream>#include<stdio.h>#include<algorithm>#include<string.h>#include<string>#include<map>#include<set>#include<vector>using namespace std;bool p[50005];int d[50005];int n,m;int dnum;set<int> s;int main(){ scanf("%d%d",&n,&m); dnum=0; string str; int num; for(int i=1;i<=n;i++){p[i]=1;} for(int i=0;i<m;i++){ cin>>str; if(str=="D"){scanf("%d",&num); d[dnum++]=num; s.insert(num); p[num]=0; } else if(str=="Q"){ scanf("%d",&num); if(p[num]==0){新聞熱點
疑難解答