Kertotaulu

#include <iostream>

using namespace std;

typedef long long int ll;

const ll mod = 1000000007;

ll modadd(ll a, ll b) {
    return (a + b) % mod;
}
ll modsub(ll a, ll b) {
    return ((a - b) % mod + mod) % mod;
}
ll modmul(ll a, ll b) {
    return (a*b) % mod;
}
ll modpow(ll b, ll e) {
    if (e == 0)
        return 1;
    if (e == 1)
        return b;
    if (e % 2 == 0) {
        ll p = modpow(b, e / 2);
        return modmul(p, p);
    }
    return modmul(modpow(b, e / 2), modpow(b, e / 2 + 1));
}
ll modinv(ll a) {
    return modpow(a, mod - 2);
}
ll moddiv(ll a, ll b) {
    return modmul(a, modinv(b));
}

ll pointsum(ll a, ll b) {
    if (a <= 0 || b <= 0)
        return 0;
    a = moddiv(modmul(a, a + 1), 2);
    b = moddiv(modmul(b, b + 1), 2);
    return modmul(a, b);
}

ll areasum(ll a, ll b, ll c, ll d) {
    return modsub(modadd(pointsum(c, d), pointsum(a - 1, b - 1)), modadd(pointsum(c, b - 1), pointsum(a - 1, d)));
}

int main() {
    ll a, b, c, d;
    cin >> a >> b >> c >> d;
    cout << areasum(a, b, c, d);
}

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: ACCEPTED

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: ACCEPTED

Test 15

Group: 3

Verdict: ACCEPTED