Files
OI-source/2.12657.cpp
2023-08-03 09:22:52 +08:00

59 lines
1.1 KiB
C++

#include<cstdio>
#include<algorithm>
using namespace std;
const int maxn=100005;
int left[maxn],right[maxn];
int n,m,kase;
inline int link(int a,int b)
{
right[a]=b;
left[b]=a;
}
int main()
{
#ifdef local
freopen("pro.in","r",stdin);
#endif
while(scanf("%d%d",&n,&m)==2)
{
for(int i=1;i<=n;i++)
{
left[i]=i-1;
right[i]=(i+1)%(n+1);
}
right[0]=1;left[0]=n;
int op,X,Y,inv=0;
while(m-->0)
{
scanf("%d",&op);
if(op==4) inv=!inv;
else
{
scanf("%d%d",&X,&Y);
if(op==3&&right[Y]==X) swap(X,Y);
if(op!=3&&inv) op=3-op;
if(op==1&&X==left[Y]) continue;
if(op==2&&X==right[Y]) continue;
int LX=left[X],RX=right[X],LY=left[Y],RY=right[Y];
if(op==1) link(LX,RX),link(LY,X),link(X,Y);
if(op==2) link(LX,RX),link(Y,X),link(X,RY);
if(op==3)
{
if(right[X]==Y) link(LX,Y),link(Y,X),link(X,RY);
else link(LX,Y),link(Y,RX),link(LY,X),link(X,RY);
}
}
}
int b=0;
long long ans=0;
for(int i=1;i<=n;i++)
{
b=right[b];
if(i&1) ans+=b;
}
if(inv&&!(n&1)) ans=(long long)n*(n+1)/2-ans;
printf("Case %d: %lld\n",++kase,ans);
}
return 0;
}