Language: C++

#include<bits/stdc++.h>

typedef unsigned int uint;
typedef long long ll;
typedef unsigned long long ull;
typedef double lf;
typedef long double llf;
typedef std::pair<int,int> pii;

#define xx first
#define yy second

template<typename T> inline T max(T a,T b){return a>b?a:b;}
template<typename T> inline T min(T a,T b){return a<b?a:b;}
template<typename T> inline T abs(T a){return a>0?a:-a;}
template<typename T> inline bool repr(T &a,T b){return a<b?a=b,1:0;}
template<typename T> inline bool repl(T &a,T b){return a>b?a=b,1:0;}
template<typename T> inline T gcd(T a,T b){T t;if(a<b){while(a){t=a;a=b%a;b=t;}return b;}else{while(b){t=b;b=a%b;a=t;}return a;}}
template<typename T> inline T sqr(T x){return x*x;}
#define mp(a,b) std::make_pair(a,b)
#define pb push_back
#define I inline
#define mset(a,b) memset(a,b,sizeof(a))
#define mcpy(a,b) memcpy(a,b,sizeof(a))

#define fo0(i,n) for(int i=0,i##end=n;i<i##end;i++)
#define fo1(i,n) for(int i=1,i##end=n;i<=i##end;i++)
#define fo(i,a,b) for(int i=a,i##end=b;i<=i##end;i++)
#define fd0(i,n) for(int i=(n)-1;~i;i--)
#define fd1(i,n) for(int i=n;i;i--)
#define fd(i,a,b) for(int i=a,i##end=b;i>=i##end;i--)
#define foe(i,x)for(__typeof((x).end())i=(x).begin();i!=(x).end();++i)

struct Cg{I char operator()(){return getchar();}};
struct Cp{I void operator()(char x){putchar(x);}};
#define OP operator
#define RT return *this;
#define RX x=0;char t=P();while((t<'0'||t>'9')&&t!='-')t=P();bool f=0;\
if(t=='-')t=P(),f=1;x=t-'0';for(t=P();t>='0'&&t<='9';t=P())x=x*10+t-'0'
#define RL if(t=='.'){lf u=0.1;for(t=P();t>='0'&&t<='9';t=P(),u*=0.1)x+=u*(t-'0');}if(f)x=-x
#define RU x=0;char t=P();while(t<'0'||t>'9')t=P();x=t-'0';for(t=P();t>='0'&&t<='9';t=P())x=x*10+t-'0'
#define TR *this,x;return x;
I bool IS(char x){return x==10||x==13||x==' ';}template<typename T>struct Fr{T P;I Fr&OP,(int&x)
{RX;if(f)x=-x;RT}I OP int(){int x;TR}I Fr&OP,(ll &x){RX;if(f)x=-x;RT}I OP ll(){ll x;TR}I Fr&OP,(char&x)
{for(x=P();IS(x);x=P());RT}I OP char(){char x;TR}I Fr&OP,(char*x){char t=P();for(;IS(t);t=P());if(~t){for(;!IS
(t)&&~t;t=P())*x++=t;}*x++=0;RT}I Fr&OP,(lf&x){RX;RL;RT}I OP lf(){lf x;TR}I Fr&OP,(llf&x){RX;RL;RT}I OP llf()
{llf x;TR}I Fr&OP,(uint&x){RU;RT}I OP uint(){uint x;TR}I Fr&OP,(ull&x){RU;RT}I OP ull(){ull x;TR}};Fr<Cg>in;
#define WI(S) if(x){if(x<0)P('-'),x=-x;char s[S],c=0;while(x)s[c++]=x%10+'0',x/=10;while(c--)P(s[c]);}else P('0')
#define WL if(y){lf t=0.5;for(int i=y;i--;)t*=0.1;if(x>=0)x+=t;else x-=t,P('-');*this,(ll)(abs(x));P('.');if(x<0)\
x=-x;while(y--){x*=10;x-=floor(x*0.1)*10;P(((int)x)%10+'0');}}else if(x>=0)*this,(ll)(x+0.5);else *this,(ll)(x-0.5);
#define WU(S) if(x){char s[S],c=0;while(x)s[c++]=x%10+'0',x/=10;while(c--)P(s[c]);}else P('0')
template<typename T>struct Fw{T P;I Fw&OP,(int x){WI(10);RT}I Fw&OP()(int x){WI(10);RT}I Fw&OP,(uint x){WU(10);RT}
I Fw&OP()(uint x){WU(10);RT}I Fw&OP,(ll x){WI(19);RT}I Fw&OP()(ll x){WI(19);RT}I Fw&OP,(ull x){WU(20);RT}I Fw&OP()
(ull x){WU(20);RT}I Fw&OP,(char x){P(x);RT}I Fw&OP()(char x){P(x);RT}I Fw&OP,(const char*x){while(*x)P(*x++);RT}
I Fw&OP()(const char*x){while(*x)P(*x++);RT}I Fw&OP()(lf x,int y){WL;RT}I Fw&OP()(llf x,int y){WL;RT}};Fw<Cp>out;

const int N=2000077,P=1000000007;

inline int pow(int a,int b)
{
	int r=1;
	for(;b;b>>=1,a=(ll)a*a%P)
		if(b&1)r=(ll)r*a%P;
	return r;
}

struct data
{
	int x,y,v;
};

int fac[N],fin[N];
int x1,x2,x3,x4,x5,x6,y1,y2,y3,y4,y5,y6,xa,ya,xb,yb;

inline int F(int a,int b)
{
	if(a>=0&&b>=0)return (ll)fac[a+b]*fin[a]%P*fin[b]%P;
	return 0;
}

inline int cal(int x,int y,int xp,int yp)
{
	//out,"cal:",x,' ',y,' ',(ll)F(x-xa,y-ya)*F(xb-x-xp,yb-y-yp)%P,'\n';
	return(ll)F(x-xa,y-ya)*F(xb-x-xp,yb-y-yp)%P;
}

inline int solve()
{
	//out,"solve:",xa,' ',ya,' ',xb,' ',yb,'\n';
	int res=0;
	fo(i,x3+1,x4)res=(res+(ll)cal(i,y3-1,0,1)*(P-i-y3))%P;
	fo(i,x3,x4-1)res=(res+(ll)cal(i,y4,0,1)*(i+y4+1))%P;
	fo(i,y3+1,y4)res=(res+(ll)cal(x3-1,i,1,0)*(P-i-x3))%P;
	fo(i,y3,y4-1)res=(res+(ll)cal(x4,i,1,0)*(i+x4+1))%P;
	res=(res+(ll)cal(x3,y3,0,0)*(P-x3-y3)+(ll)cal(x4,y4,0,0)*(x4+y4+1))%P;
	return res;
}

int main()
{
	fac[0]=1;
	fo1(i,N-1)fac[i]=(ll)fac[i-1]*i%P;
	fin[N-1]=pow(fac[N-1],P-2);
	fd1(i,N-1)fin[i-1]=(ll)fin[i]*i%P;
	in,x1,x2,x3,x4,x5,x6,y1,y2,y3,y4,y5,y6;
	//xa=1,ya=1,xb=3,yb=4;
	//out,solve(),'\n';
	//return 0;
	data a[4],b[4];
	a[0]=(data){x1-1,y1-1,1};
	a[1]=(data){x1-1,y2,-1};
	a[2]=(data){x2,y1-1,-1};
	a[3]=(data){x2,y2,1};
	b[0]=(data){x6+1,y6+1,1};
	b[1]=(data){x6+1,y5,-1};
	b[2]=(data){x5,y6+1,-1};
	b[3]=(data){x5,y5,1};
	ll ans=0;
	fo0(i,4)fo0(j,4)xa=a[i].x,ya=a[i].y,xb=b[j].x,yb=b[j].y,ans+=solve()*a[i].v*b[j].v;
	out,(ans%P+P)%P,'\n';
}

Compiler output:
a.cc:73:23: error: 'int y1' redeclared as different kind of entity
   73 | int x1,x2,x3,x4,x5,x6,y1,y2,y3,y4,y5,y6,xa,ya,xb,yb;
      |                       ^~
In file included from /usr/include/features.h:523,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/os_defines.h:39,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/c++config.h:683,
                 from /usr/include/c++/14/cassert:43,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:33,
                 from a.cc:1:
/usr/include/x86_64-linux-gnu/bits/mathcalls.h:257:1: note: previous declaration 'double y1(double)'
  257 | __MATHCALL (y1,, (_Mdouble_));
      | ^~~~~~~~~~
a.cc: In function 'int main()':
a.cc:110:28: warning: pointer to a function used in arithmetic [-Wpointer-arith]
  110 |         a[0]=(data){x1-1,y1-1,1};
      |                          ~~^~
a.cc:110:28: error: invalid conversion from 'double (*)(double) noexcept' to 'int' [-fpermissive]
  110 |         a[0]=(data){x1-1,y1-1,1};
      |                          ~~^~
      |                            |
      |                            double (*)(double) noexcept
a.cc:112:26: warning: pointer to a function used in arithmetic [-Wpointer-arith]
  112 |         a[2]=(data){x2,y1-1,-1};
      |                        ~~^~
a.cc:112:26: error: invalid conversion from 'double (*)(double) noexcept' to 'int' [-fpermissive]
  112 |         a[2]=(data){x2,y1-1,-1};
      |                        ~~^~
      |                          |
      |                          double (*)(double) noexcept