QOJ.ac

QOJ

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
#90971#5458. Shortest Path QueryIndusWA 51ms28860kbC++142.0kb2023-03-26 11:10:462024-06-21 12:37:52

Judging History

你现在查看的是最新测评结果

  • [2024-06-21 12:37:52]
  • 管理员手动重测本题所有提交记录
  • 测评结果:WA
  • 用时:51ms
  • 内存:28860kb
  • [2023-08-10 23:21:45]
  • System Update: QOJ starts to keep a history of the judgings of all the submissions.
  • [2023-03-26 11:10:50]
  • 评测
  • 测评结果:0
  • 用时:100ms
  • 内存:28620kb
  • [2023-03-26 11:10:46]
  • 提交

answer

#include <bits/stdc++.h>
#define eb emplace_back
#define fi first
#define se second
#define pii pair<int, int>
#define mp make_pair
using namespace std;

template<typename Tp>
void read(Tp &x) {
    x = 0; char ch = getchar(); int f = 0;
    for(; !isdigit(ch); f |= (ch == '-'), ch = getchar());
    for(; isdigit(ch); x = (x<<3)+(x<<1)+(ch^48), ch = getchar());
    if (f) x = ~x + 1;
}

typedef long long LL;
const LL inf = 9e18;
const int N = 1e5 + 5;
int n, m, deg[N];
vector<pii> G[N], vec[N];

double slope(pii i, pii j) {
    if (i.fi == j.fi) return inf;
    return 1.0 * (i.se - j.se) / (i.fi - j.fi);
}
pii operator + (const pii &a, const pii &b) {return mp(a.fi + b.fi, a.se + b.se);}

void TopuSort() {
    queue<int> Q; Q.push(1), vec[1].eb(mp(0, 0));
    while (!Q.empty()) {
        int x = Q.front(); Q.pop();
        sort(vec[x].begin(), vec[x].end());
        vector<pii> f;
        for(pii k : vec[x]) {
            while (f.size() > 1 && slope(f.back(), f[f.size() - 2]) >= slope(k, f.back())) f.pop_back();
            f.eb(k);
        }
        swap(vec[x], f);
        for(pii e : G[x]) {
            for(pii k : vec[x]) {
                vec[e.fi].eb(k + mp(!e.se, e.se)), --deg[e.fi];
                if (!deg[e.fi]) Q.push(e.fi);
            }
        }
    }
}

int calc(int a, int b, pii k){return a * k.fi + b * k.se;}
int Query(int u, int a, int b) {
    if (vec[u].size() == 1) calc(a, b, vec[u][0]);
    double k = -1.0 * a / b;
    int l = 0, r = vec[u].size() - 2, mid = l + r >> 1, bst = 0;
    for(; l <= r; mid = l + r >> 1)
        if (slope(vec[u][mid], vec[u][mid + 1]) >= k) bst = mid, r = mid - 1; else l = mid + 1;
    return min(calc(a, b, vec[u][bst]), calc(a, b, vec[u].back()));
}

int main() {
    read(n), read(m);
    for(int i = 1, u, v, w; i <= m; i++) read(u), read(v), read(w), G[u].eb(mp(v, w)), ++deg[v];
    TopuSort(); int q; read(q);
    for(int a, b, u; q; --q) read(a), read(b), read(u), printf("%d\n", Query(u, a, b));
}

详细

Test #1:

score: 100
Accepted
time: 0ms
memory: 8396kb

input:

4 4
1 2 0
1 3 1
2 4 0
3 4 1
3
3 5 2
3 2 4
2 3 4

output:

3
4
4

result:

ok 3 number(s): "3 4 4"

Test #2:

score: 0
Accepted
time: 39ms
memory: 17628kb

input:

50000 100000
1 2 1
2 3 0
3 4 1
4 5 0
5 6 1
6 7 0
7 8 1
8 9 1
9 10 0
10 11 1
11 12 1
12 13 1
13 14 0
14 15 0
15 16 0
16 17 0
17 18 1
18 19 1
19 20 0
20 21 1
21 22 0
22 23 0
23 24 1
24 25 1
25 26 0
26 27 1
27 28 0
28 29 0
29 30 0
30 31 0
31 32 1
32 33 0
33 34 1
34 35 1
35 36 1
36 37 1
37 38 0
38 39 0
...

output:

164602050
208733870
228180204
248456409
87574800
16685198
46684062
64713954
46949896
240633535
94777502
83016099
259833741
167838804
214963500
147454419
111021650
80187604
184782450
78138570
86528820
203553394
188095596
202049239
290053220
172790198
168899028
97757186
96431009
266952297
164349486
26...

result:

ok 50000 numbers

Test #3:

score: -100
Wrong Answer
time: 51ms
memory: 28860kb

input:

50000 100000
1 2 1
2 3 0
3 4 1
4 5 0
5 6 0
6 7 1
7 8 0
8 9 0
9 10 1
10 11 1
11 12 1
12 13 1
13 14 0
14 15 1
15 16 1
16 17 1
17 18 0
18 19 0
19 20 1
20 21 1
21 22 1
22 23 0
23 24 0
24 25 1
25 26 1
26 27 0
27 28 0
28 29 1
29 30 0
30 31 1
31 32 1
32 33 1
33 34 0
34 35 1
35 36 1
36 37 1
37 38 0
38 39 0
...

output:

100398788
31414635
97057314
4877973
131372151
101401294
97972523
116465260
89286626
138309577
111227766
96931397
98894394
113784862
103437724
35891862
119591018
27385428
145395927
53389420
44991380
178247166
102795173
124131241
70849452
29005113
62367612
55557236
83480745
101099140
24142023
82761051...

result:

wrong answer 1st numbers differ - expected: '100196045', found: '100398788'