Kertotaulu

#include <iostream>

using namespace std;

#define ll long long
#define N 1000000007

ll y1,x1,y2,x2;
ll row,col;

ll pot(ll x, int n) {
	if (n == 0) return 1;
	if (n%2 == 1) return (pot(x,n-1)*x)%N;
	ll t = pot(x,n/2);
	return (t*t)%N;
}

ll inv(ll x) {
	return pot(x, N-2);
}

int main()
{
	cin >> y1 >> x1 >> y2 >> x2;
	//row = ((((x2%N+1)%N-x1%N)%N*(x2%N+x1%N)%N)%N/2)%N;
	//col = ((((y2%N+1)%N-y1%N)%N*(y2%N+y1%N)%N)%N/2)%N;
	row = (x2%N*(x2%N+1)%N)%N-(x1%N*(x1%N-1)%N)%N;
	col = (y2%N*(y2%N+1)%N)%N-(y1%N*(y1%N-1)%N)%N;
	cout << (((row*col)%N)*inv(4))%N << "\n";
}

Test 1

Group: 1

Verdict: ACCEPTED

Test 2

Group: 1

Verdict: ACCEPTED

Test 3

Group: 1

Verdict: ACCEPTED

Test 4

Group: 1

Verdict: ACCEPTED

Test 5

Group: 1

Verdict: ACCEPTED

Test 6

Group: 2

Verdict: WRONG ANSWER

Test 7

Group: 2

Verdict: ACCEPTED

Test 8

Group: 2

Verdict: ACCEPTED

Test 9

Group: 2

Verdict: ACCEPTED

Test 10

Group: 2

Verdict: ACCEPTED

Test 11

Group: 3

Verdict: ACCEPTED

Test 12

Group: 3

Verdict: ACCEPTED

Test 13

Group: 3

Verdict: ACCEPTED

Test 14

Group: 3

Verdict: WRONG ANSWER

Test 15

Group: 3

Verdict: ACCEPTED