题意：把一个多边形往里面连对角线，然后问每次添加多边形被划分为几个部分
产生的部分就是新加对角线与原有对角线相交条数+1，用线段树（大雾）维护一下。
1 #include<bits/stdc++.h> 2 #define LL long long 3 #define N 100005 4 #define lowbit(x) x&(-x) 5 using namespace std; 6 inline LL ra() 7 { 8 LL x=0,f=1; char ch=getchar(); 9 while (ch<'0' || ch>'9') {if (ch=='-') f=-1; ch=getchar();} 10 while (ch>='0' && ch<='9') {x=x*10+ch-'0'; ch=getchar();} 11 return x*f; 12 } 13 LL n,k; 14 struct node{ 15 LL tag,sum,l,r; 16 }t[N<<6]; 17 LL T,ans=1; 18 void build(LL k, LL l, LL r) 19 { 20 t[k].l=l; t[k].r=r; 21 if (l==r) return; 22 LL mid=l+r>>1; 23 build(k<<1,l,mid); build(k<<1|1,mid+1,r); 24 } 25 void update(LL k) 26 { 27 t[k].sum=t[k<<1].sum+t[k<<1|1].sum; 28 } 29 void pushdown(LL k) 30 { 31 LL tmp=t[k].tag; t[k].tag=0; 32 t[k<<1].tag+=tmp; t[k<<1|1].tag+=tmp; 33 t[k<<1].sum+=(t[k<<1].r-t[k<<1].l+1)*tmp; 34 t[k<<1|1].sum+=(t[k<<1|1].r-t[k<<1|1].l+1)*tmp; 35 } 36 void change(LL k, LL x, LL y, LL val) 37 { 38 if (x>y || y>n) return; 39 LL l=t[k].l,r=t[k].r; 40 if (l==x && y==r) 41 { 42 t[k].tag+=val; 43 t[k].sum+=(r-l+1)*val; 44 return; 45 } 46 if (t[k].tag) pushdown(k); 47 LL mid=l+r>>1; 48 if (y<=mid) change(k<<1,x,y,val); 49 else if (x>mid) change(k<<1|1,x,y,val); 50 else{ 51 change(k<<1,x,mid,val); 52 change(k<<1|1,mid+1,y,val); 53 } 54 update(k); 55 } 56 LL ask(LL k, LL x, LL y) 57 { 58 if (x>y || y>n) return 0; 59 LL l=t[k].l,r=t[k].r; 60 if (x==l && y==r) return t[k].sum; 61 if (t[k].tag) pushdown(k); 62 LL mid=l+r>>1; 63 if (y<=mid) return ask(k<<1,x,y); 64 else if (x>mid) return ask(k<<1|1,x,y); 65 else return ask(k<<1,x,mid)+ask(k<<1|1,mid+1,y); 66 } 67 int main() 68 { 69 LL last=1,aim; 70 T=n=ra(); k=ra(); 71 if (k>n/2) k=n-k; 72 build(1,1,n); 73 while (T--) 74 { 75 LL aim=(last+k-1)%n+1; 76 if (aim>last) 77 { 78 ans+=ask(1,last+1,aim-1)+1; 79 change(1,last,last,1); 80 change(1,aim,aim,1); 81 } 82 else 83 { 84 ans+=ask(1,last+1,n)+ask(1,1,aim-1)+1; 85 change(1,last,last,1); change(1,aim,aim,1); 86 } 87 last=aim; 88 printf("%I64d ",ans); 89 // cout<<ask(2); system("pause"); 90 } 91 return 0; 92 }