QOJ.ac

QOJ

IDProblemSubmitterResultTimeMemoryLanguageFile sizeSubmit timeJudge time
#751313#6744. SquareXfJbUhpyzgaW#AC ✓60ms3656kbC++171.5kb2024-11-15 18:04:552024-11-15 18:04:56

Judging History

你现在查看的是最新测评结果

  • [2024-11-15 18:04:56]
  • 评测
  • 测评结果:AC
  • 用时:60ms
  • 内存:3656kb
  • [2024-11-15 18:04:55]
  • 提交

answer

#include <bits/stdc++.h>
using namespace std;


#define F(i, a, b) for (int i = (a), iee = (b); i <= iee; i++)
#define R(i, a, b) for (int i = (a), iee = (b); i >= iee; i--)

using ll = long long;

const int N = 100100;
int n, a[N];
ll b[N], x[N];

ll exgcd(ll a, ll b, ll &x, ll &y) {
    if (!b) {
        x = 1, y = 0;
        return a;
    }
    ll g = exgcd(b, a % b, y, x);
    y -= a / b * x;
    return g;
}

int gt(ll x) {
    ll l = 1, r = 2e9;
    while (l < r - 1) {
        ll t = (l + r) >> 1;
        if (t * (t - 3) / 2 + 2 <= x)
            l = t;
        else
            r = t;
    }
    //assert(l == floor(sqrt(x * 2) + 1.5));
    return l;
}
pair<ll, ll> get(ll t) {
    return {t * (t - 3) / 2 + 2, t * (t - 1) / 2};
}

ll calc(ll x, ll y) {
    ll tx = gt(x), ty = gt(y);
    auto gy = get(ty), gx = get(tx);
    x += gy.second - gx.second;
    ll ans = ty - tx + x - y;
    if (x < y)
        ans += gy.second - gy.first + 2;
    return ans;
}

int main() {
    cin.tie(0)->sync_with_stdio(0), cout.tie(0);
    //F(i, 1, 20) cout << get(gt(i)).first << " "; cout << endl;
    int T;
    for (cin >> T; T; T--) {
        ll x, y;
        cin >> x >> y;
        if (x >= y) { cout << x - y << "\n"; continue; }
        auto gx = get(gt(x));
        ll ans = calc(x, y);
        if (x > 1) ans = min(ans, x - gx.first + 1 + calc(gx.first - 1, y));
        cout << ans << "\n";
    }
}

// y-1/2-sqrt(2y-2)<=x<y+1/2-sqrt(2y)

Details

Tip: Click on the bar to expand more detailed information

Test #1:

score: 100
Accepted
time: 0ms
memory: 3584kb

input:

2
5 1
1 5

output:

4
3

result:

ok 2 number(s): "4 3"

Test #2:

score: 0
Accepted
time: 60ms
memory: 3656kb

input:

100000
1 1
1 2
1 3
1 4
1 5
1 6
1 7
1 8
1 9
1 10
1 11
1 12
1 13
1 14
1 15
1 16
1 17
1 18
1 19
1 20
1 21
1 22
1 23
1 24
1 25
1 26
1 27
1 28
1 29
1 30
1 31
1 32
1 33
1 34
1 35
1 36
1 37
1 38
1 39
1 40
1 41
1 42
1 43
1 44
1 45
1 46
1 47
1 48
1 49
1 50
1 51
1 52
1 53
1 54
1 55
1 56
1 57
1 58
1 59
1 60
1 ...

output:

0
2
1
4
3
2
6
5
4
3
8
7
6
5
4
10
9
8
7
6
5
12
11
10
9
8
7
6
14
13
12
11
10
9
8
7
16
15
14
13
12
11
10
9
8
18
17
16
15
14
13
12
11
10
9
20
19
18
17
16
15
14
13
12
11
10
22
21
20
19
18
17
16
15
14
13
12
11
24
23
22
21
20
19
18
17
16
15
14
13
12
26
25
24
23
22
21
20
19
18
1
0
2
2
1
3
4
3
2
4
6
5
4
3
5
...

result:

ok 100000 numbers