不知道在干什么
#pragma optimize("-O2") #include<bits/stdc++.h> #define LL long long #define int LL #define N 2007 #define mo 100000007 #define sight(c) ('0'<=c&&c<='9') #define min(a,b) ((a)<(b)?(a):(b)) using namespace std; LL n,m,k; struct Point { int x, y; Point(int a = 0, int b = 0) : x(a), y(b) { } bool operator< (const Point &b) const& { return x < b.x || x == b.x && y < b.y; } bool operator== (const Point &b) const& { return x == b.x && y == b.y; } inline bool in(){ return 0<=x&&x<=n&&0<=y&&y<= m; } }pt[N]; set<Point> mp; inline void read(LL &x){ static char c; for (c=getchar();!sight(c);c=getchar()); for (x=0;sight(c);c=getchar()) x=x*10+c-48; } //inline void read(int &x){ // static char c; // for (c=getchar();!sight(c);c=getchar()); // for (x=0;sight(c);c=getchar()) x=x*10+c-48; //} void write(int x){ if (x<10) { putchar('0'+x);return;} write(x/10),putchar('0'+x%10); } inline void writeln(int x){ if (x<0) putchar('-'),x*=-1; write(x); putchar(' '); } LL NO() { int k=min(n, m); LL ans = 0; for (int i=1;i<=k;++i) (ans+=(n-i+1)*(m-i+1)%mo*i)%=mo; return ans; } LL COP(int l, int r, int h) { int z=min(l+r,h); if (z==0) return 0; LL ans=z*(z+3)>>1; if (z>l) ans-=(z-l)*(z-l+1)>>1; if (z>r) ans-=(z-r)*(z-r+1)>>1; return ans; } LL OOO(int x, int y) { int t = x, b = n - x, l = y, r = m - y; LL tog=(COP(t,b,l)+COP(t,b,r)+COP(l,r,t) + COP(l, r, b) -min(l,t)-min(t,r)-min(r,b)-min(b,l))%mo; return tog; } void CN(Point a, Point b, int &cnt2, int &cnt3, int &cnt4) { if (a.in()&&b.in()) { int t = mp.count(a) + mp.count(b); ++cnt2; if (t>0) ++cnt3; if (t>1) ++cnt4, ++cnt3; } } LL dx,dy,x,y; signed main() { // freopen("BB.in","r",stdin); read(n); read(m); read(k); LL ans=NO(); for (int i=0;i<k;i++) { read(pt[i].x); read(pt[i].y); mp.insert(pt[i]); (ans-=OOO(pt[i].x, pt[i].y))%=mo; } int cnt2=0,cnt3=0,cnt4=0; for (int i=0;i<k;i++) { Point p=pt[i]; for (int j=i+1;j<k;j++) { Point q=pt[j]; dx=p.x-q.x,dy=p.y-q.y; CN(Point(p.x+dy,p.y-dx),Point(q.x+dy,q.y-dx),cnt2,cnt3,cnt4); CN(Point(p.x-dy,p.y+dx),Point(q.x-dy,q.y+dx),cnt2,cnt3,cnt4); if ((abs(dx)+abs(dy))&1) continue; x=dx-dy>>1,y=dx+dy>>1; CN(Point(p.x-x,p.y-y),Point(q.x+x,q.y+y),cnt2,cnt3,cnt4); } } ans=(ans+cnt2-cnt3/3+cnt4/6)%mo; if (ans<0) ans+=mo; writeln(ans); }