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ID题目提交者结果用时内存语言文件大小提交时间测评时间
#730595#9520. Concave Hullsilver_museAC ✓74ms13368kbC++203.1kb2024-11-09 20:46:292024-11-09 20:46:31

Judging History

你现在查看的是最新测评结果

  • [2024-11-09 20:46:31]
  • 评测
  • 测评结果:AC
  • 用时:74ms
  • 内存:13368kb
  • [2024-11-09 20:46:29]
  • 提交

answer

#include<bits/stdc++.h>
using namespace std;
typedef long long i64;

struct point {
    i64 x, y;
    point(i64 x = 0, i64 y = 0): x(x), y(y) {}
    i64 hval() {return ((x + 1000000000LL) << 31) | (y + 1000000000LL);}
};

struct arrow {
    i64 x, y;
    arrow(i64 x = 0, i64 y = 0): x(x), y(y) {}
    arrow(point a, point b): x(b.x - a.x), y(b.y - a.y) {}
};

bool operator == (const point &a, const point &b) {
    return a.x == b.x && a.y == b.y;
}
bool operator < (const point &a, const point &b) {
    if(a.x == b.x) return a.y < b.y;
    else return a.x < b.x;
}
i64 dot(const arrow &a, const arrow &b) {
    return a.x * b.x + a.y * b.y;
}
i64 cross(const arrow &a, const arrow &b) {
    return a.x * b.y - a.y * b.x;
}
// 三角形面积的两倍
i64 area(const point &a, const point &b, const point &c) {
    return abs(cross({a, b}, {a, c}));
}

// 将参数 v 变成一个凸包,逆时针排序,v[0] 是坐标最小的点
void makeConvex(vector<point> &v) {
    sort(v.begin(), v.end());
    v.erase(unique(v.begin(), v.end()), v.end());
    vector<point> t;
    for(int cnt = 0; cnt < 2; cnt++) {
        reverse(v.begin(), v.end());
        stack<point> p; stack<arrow> e;
        p.push(v[0]);
        for(int i = 1; i < v.size(); i++) {
            // 下面这个 while 会导致凸包上任意三个点都不在同一个直线上
            // 如果需要保留凸包边中间的点,把 >= 改成 > 即可
            while(!e.empty() && cross(e.top(), {p.top(), v[i]}) >= 0) 
                p.pop(), e.pop();
            e.push(arrow(p.top(), v[i]));
            p.push(v[i]);
        }
        while(p.size() > 1) 
            t.push_back(p.top()), p.pop();
    }
    v = t;
}

void solve() {
    i64 n, ans = 0, mint = 8e18; cin >> n;
    vector<point> v, t, temp;
    unordered_set<i64> mp;
    for(int i = 1; i <= n; i++) {
        i64 x, y; cin >> x >> y;
        v.push_back({x, y});
        temp.push_back({x, y});
    }
    makeConvex(v); v.push_back(v[0]);
    for(int i = 1; i < v.size(); i++) {
        ans += area(v[0], v[i], v[i - 1]);
    }
    for(auto p : v) {
        mp.insert(p.hval());
    }
    for(auto p : temp) {
        if(!mp.count(p.hval())) t.push_back(p);
    }
    if(t.size() == 0) {cout << "-1" << endl; return;}
    else if(t.size() < 3) {
        for(auto p : t) for(int i = 1; i < v.size(); i++)
            mint = min(mint, area(p, v[i], v[i - 1]));
        cout << ans - mint << endl;
    } else {
        makeConvex(t); int szt = t.size(), p = 0;
        for(int i = 0; i < szt * 2; i++) {
            t.push_back(t[i]);
        }
        for(int i = 0; i < szt; i++) {
            if(area(v[0], v[1], t[i]) < area(v[0], v[1], t[p])) p = i;
        }
        for(int i = 1; i < v.size(); i++) {
            while(area(v[i], v[i - 1], t[p + 1]) <= area(v[i], v[i - 1], t[p])) p++;
            mint = min(mint, area(v[i], v[i - 1], t[p]));
        }
        cout << ans - mint << endl;
    }
}

int main() {
    ios::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);
    int T; cin >> T;
    while(T--) solve();
    return 0;
}

这程序好像有点Bug,我给组数据试试?

詳細信息

Test #1:

score: 100
Accepted
time: 0ms
memory: 3640kb

input:

2
6
-2 0
1 -2
5 2
0 4
1 2
3 1
4
0 0
1 0
0 1
1 1

output:

40
-1

result:

ok 2 lines

Test #2:

score: 0
Accepted
time: 1ms
memory: 3596kb

input:

10
243
-494423502 -591557038
-493438474 -648991734
-493289308 -656152126
-491185085 -661710614
-489063449 -666925265
-464265894 -709944049
-447472922 -737242534
-415977509 -773788538
-394263365 -797285016
-382728841 -807396819
-373481975 -814685302
-368242265 -818267002
-344482838 -833805545
-279398...

output:

2178418010787347715
1826413114144932145
1651687576234220014
1883871859778998985
2119126281997959892
894016174881844630
2271191316922158910
1998643358049669416
1740474221286618711
1168195646932543192

result:

ok 10 lines

Test #3:

score: 0
Accepted
time: 33ms
memory: 3948kb

input:

1000
125
64661186 -13143076
302828013 -185438065
-418713797 -191594241
430218126 -397441626
354327250 -836704374
149668812 -598584998
311305970 66790541
199720625 -592356787
468137 -584752683
258775829 96211747
-358669612 -134890109
-129221188 -998432368
-277309896 -140056561
356901185 420557649
-51...

output:

1986320445246155278
1900093336073022078
1612088392301142476
2012259136539173407
1819942017252118749
1772230185841892196
1164835025329039520
1527446155241140517
1807368432185303666
1236918659444944569
1306839249967484778
1984123720246784099
1868728080720036006
667458140583450322
2127932992585026491
4...

result:

ok 1000 lines

Test #4:

score: 0
Accepted
time: 52ms
memory: 3620kb

input:

10000
9
484630042 51929469
-40468396 -517784096
98214104 -103353239
629244333 -475172587
106398764 153884485
49211709 -44865749
1 10
166321833 -247717657
406208245 668933360
13
548702216 -631976459
37150086 -292461024
707804811 -486185860
239775286 -903166050
10096571 -541890068
686103484 558731937
...

output:

950319193795831919
1661025342421008544
1285164852091455548
1159924751776806668
1206071151805176722
794021230296144371
699991678992587791
1133990718508584290
1486311831172661605
984875884297072200
1327767982175057345
758247019006396699
1355381234262206155
1139262078529131471
1613462877860621700
12392...

result:

ok 10000 lines

Test #5:

score: 0
Accepted
time: 66ms
memory: 4392kb

input:

100
439
471536154 -312612104
155692036 -937312180
-461624056 -357636609
236656684 -911414873
-288656914 -74788431
-465779694 -381475149
-334197401 -903065737
491513067 -447615916
337664889 -852236281
-281689379 -53519178
-159101704 -920779200
-326159514 -95396204
21868593 -994282736
488425383 -41046...

output:

1973162724053130487
2054612790507830954
1726805687754843724
1699420177872986528
2129388571309147631
2198295137903288810
1697185883164440272
1219697450095721478
2027023581922285255
1674691247127206655
1673105966817209954
2179188692918747442
2146544318743443141
2230356305133660648
1676850321902993764
...

result:

ok 100 lines

Test #6:

score: 0
Accepted
time: 51ms
memory: 4336kb

input:

100
1362
-467257672 -466669
-467054869 -478108
-466973270 -481776
-466556983 -499770
-466329414 -508693
-466248017 -511805
-466158865 -513786
-466101273 -515035
-465927700 -518748
-465717624 -522106
-465303448 -528127
-465124548 -530726
-464649746 -536693
-464554872 -537799
-464478196 -538680
-46416...

output:

1666097696993497
1791366071767866
1806187278469532
1683419854733713
1685891971828916
1730190225081651
1787048201197565
1850308098208660
1710694884375502
1826363113637639
1816375352374659
2047431269497691
1549806516003854
1829438662895747
1678707854135065
1687423392883819
2121960009997761
16687219538...

result:

ok 100 lines

Test #7:

score: 0
Accepted
time: 32ms
memory: 8336kb

input:

2
62666
-486101704 -505730259
-486101698 -506082699
-486101689 -506111362
-486101682 -506126031
-486101528 -506293759
-486101259 -506556385
-486101196 -506613483
-486101154 -506648604
-486100935 -506831392
-486100631 -507083675
-486100470 -507199151
-486100233 -507368923
-486100193 -507397039
-48609...

output:

2178736946152219010
1825181940245096152

result:

ok 2 lines

Test #8:

score: 0
Accepted
time: 62ms
memory: 11644kb

input:

2
100000
301945097 76373292
467957663 -286424714
8245445 -597212507
-474204621 -708828667
184159460 105942538
443435905 -429212625
490658771 -382198656
82512047 -612522436
-228221388 -965890088
394789011 -145801151
-106120174 -528202395
428939626 -194437311
497429477 -527407728
365739746 -114818962
...

output:

2502889432701099511
2267250485735988121

result:

ok 2 lines

Test #9:

score: 0
Accepted
time: 74ms
memory: 13368kb

input:

2
100000
221128057 -975244780
-618765360 -785575858
422567455 -906331476
-988680318 -150037424
-929870145 367887908
-757813541 -652471177
291995621 -956419655
-785381507 619012026
468864522 -883270094
-588416522 808557973
859345881 511394814
988105866 153775152
216931298 -976186873
467050734 8842305...

output:

6283183114882825575
6283183188903854361

result:

ok 2 lines

Test #10:

score: 0
Accepted
time: 1ms
memory: 3836kb

input:

7
5
-1000000000 -1000000000
1000000000 -1000000000
1000000000 1000000000
1 0
-1 0
5
1000000000 1000000000
-1000000000 -1000000000
-2 0
-1 0
1 -1
6
1000000000 1000000000
-1000000000 -1000000000
-3 0
-1 0
0 -1
1 -1
4
-1000000000 -1000000000
1000000000 -1000000000
1000000000 1000000000
-1000000000 1000...

output:

4000000000000000000
7000000000
9000000001
-1
6000000002000000000
7999999998000000000
-1

result:

ok 7 lines

Extra Test:

score: 0
Extra Test Passed