#include<cstdio>
#include<algorithm>
#include<queue>
#define N_ 2010
#define pli pair<long long,int>
using namespace std;
vector<int>E[N_], F[N_], G[N_];
vector<int>L[N_], Num[N_];
int n, m, Path[N_], chk[101000];
int SP[N_], EP[N_], imp[N_], H[N_], vv[N_];
long long SD[N_], ED[N_], D[N_], DD[101000][2], INF = 1e18, U[N_];
int ord[N_];
priority_queue<pli>PQ;
struct Edge {
int a, b, c, d;
}Ed[101000];
void Push(int a, int p, long long c) {
if (D[a] <= c)return;
D[a] = c;
Path[a] = p;
PQ.push({ -c,a });
}
void Dijk(int a) {
int i;
for (i = 1; i <= n; i++)D[i] = INF, Path[i] = 0, vv[i] = 0;
Push(a, 0, 0);
while (!PQ.empty()) {
pli tp = PQ.top();
PQ.pop();
int x = tp.second;
if (vv[x])continue;
vv[x] = 1;
for (int i = 0; i < E[x].size(); i++) {
Push(E[x][i], Num[x][i], D[x] + L[x][i]);
}
}
}
int cnt;
void DFS(int a, int pp) {
int i;
if (imp[a]) {
H[a] = a;
ord[a] = cnt--;
}
else H[a] = H[pp];
for (auto &x : G[a]) {
DFS(x, a);
}
}
void Do(int st, int ed, int ck) {
int i, j;
for (i = 1; i <= n; i++) {
G[i].clear();
E[i].clear();
F[i].clear();
L[i].clear();
Num[i].clear();
}
for (i = 1; i <= m; i++) {
E[Ed[i].a].push_back(Ed[i].b);
L[Ed[i].a].push_back(Ed[i].c);
Num[Ed[i].a].push_back(i);
}
Dijk(st);
long long d = D[ed];
DD[0][ck] = d;
for (i = 1; i <= n; i++) SD[i] = D[i];
for (i = 1; i <= n; i++) {
E[i].clear();
L[i].clear();
Num[i].clear();
}
for (i = 1; i <= m; i++) {
E[Ed[i].b].push_back(Ed[i].a);
L[Ed[i].b].push_back(Ed[i].c);
Num[Ed[i].b].push_back(i);
}
Dijk(ed);
for (i = 1; i <= n; i++) {
ED[i] = D[i];
EP[i] = Path[i];
H[i] = imp[i] = 0;
}
for (i = 1; i <= n; i++) {
if(EP[i])G[Ed[EP[i]].b].push_back(i);
}
for (i = 1; i <= m; i++)chk[i] = 0;
int x = st;
imp[st] = imp[ed] = 1;
if (d < INF) {
while (x != ed) {
imp[x] = 1;
int t = EP[x];
chk[t] = 1;
x = Ed[t].b;
}
}
for (i = 1; i <= m; i++) {
if (!chk[i]) {
DD[i][ck] = SD[Ed[i].b] + ED[Ed[i].a] + Ed[i].c;
DD[i][ck] = min(DD[i][ck], d);
}
else DD[i][ck] = INF;
}
for (i = 1; i <= n; i++)U[i] = INF;
cnt = n;
DFS(ed, 0);
for (i = 1; i <= m; i++) {
if (chk[i])continue;
int a = H[Ed[i].a], b = H[Ed[i].b];
if (ord[a] < ord[b]) {
long long t = SD[Ed[i].a] + ED[Ed[i].b] + Ed[i].c;
for (j = ord[a]; j < ord[b]; j++) {
U[j] = min(U[j], t);
}
}
}
for (i = 1; i <= m; i++) {
if (!chk[i])continue;
int a = ord[Ed[i].a], b = ord[Ed[i].b];
if (a > b)swap(a, b);
DD[i][ck] = min(DD[i][ck],U[a]);
}
}
int main() {
int i, j;
scanf("%d%d", &n, &m);
for (i = 1; i <= m; i++) {
int a, b, c, d;
scanf("%d%d%d%d", &a, &b, &c, &d);
Ed[i] = { a,b,c,d };
}
Do(1, n, 0);
Do(n, 1, 1);
long long res = INF;
for (i = 0; i <= m; i++) {
res = min(res, DD[i][0] + DD[i][1] + Ed[i].d);
}
if (res > 8e17)res = -1;
printf("%lld\n", res);
}
Compilation message
ho_t4.cpp: In function 'void Dijk(int)':
ho_t4.cpp:35:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for (int i = 0; i < E[x].size(); i++) {
~~^~~~~~~~~~~~~
ho_t4.cpp: In function 'void DFS(int, int)':
ho_t4.cpp:42:6: warning: unused variable 'i' [-Wunused-variable]
int i;
^
ho_t4.cpp: In function 'int main()':
ho_t4.cpp:136:9: warning: unused variable 'j' [-Wunused-variable]
int i, j;
^
ho_t4.cpp:137:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
scanf("%d%d", &n, &m);
~~~~~^~~~~~~~~~~~~~~~
ho_t4.cpp:140:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
scanf("%d%d%d%d", &a, &b, &c, &d);
~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
6 ms |
760 KB |
Output is correct |
2 |
Correct |
5 ms |
632 KB |
Output is correct |
3 |
Correct |
6 ms |
760 KB |
Output is correct |
4 |
Correct |
6 ms |
760 KB |
Output is correct |
5 |
Correct |
6 ms |
632 KB |
Output is correct |
6 |
Correct |
5 ms |
632 KB |
Output is correct |
7 |
Correct |
5 ms |
632 KB |
Output is correct |
8 |
Correct |
5 ms |
632 KB |
Output is correct |
9 |
Correct |
6 ms |
636 KB |
Output is correct |
10 |
Correct |
6 ms |
760 KB |
Output is correct |
11 |
Correct |
6 ms |
620 KB |
Output is correct |
12 |
Correct |
6 ms |
760 KB |
Output is correct |
13 |
Correct |
6 ms |
632 KB |
Output is correct |
14 |
Correct |
6 ms |
632 KB |
Output is correct |
15 |
Correct |
6 ms |
632 KB |
Output is correct |
16 |
Correct |
7 ms |
760 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
37 ms |
3448 KB |
Output is correct |
2 |
Correct |
39 ms |
3576 KB |
Output is correct |
3 |
Correct |
41 ms |
3448 KB |
Output is correct |
4 |
Correct |
7 ms |
760 KB |
Output is correct |
5 |
Correct |
6 ms |
760 KB |
Output is correct |
6 |
Correct |
6 ms |
760 KB |
Output is correct |
7 |
Correct |
6 ms |
632 KB |
Output is correct |
8 |
Correct |
5 ms |
632 KB |
Output is correct |
9 |
Correct |
38 ms |
3704 KB |
Output is correct |
10 |
Correct |
40 ms |
3704 KB |
Output is correct |
11 |
Correct |
39 ms |
3424 KB |
Output is correct |
12 |
Correct |
40 ms |
3540 KB |
Output is correct |
13 |
Correct |
52 ms |
3424 KB |
Output is correct |
14 |
Correct |
40 ms |
3448 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
6 ms |
760 KB |
Output is correct |
2 |
Correct |
5 ms |
632 KB |
Output is correct |
3 |
Correct |
31 ms |
2680 KB |
Output is correct |
4 |
Correct |
5 ms |
632 KB |
Output is correct |
5 |
Correct |
38 ms |
3448 KB |
Output is correct |
6 |
Correct |
5 ms |
632 KB |
Output is correct |
7 |
Correct |
5 ms |
632 KB |
Output is correct |
8 |
Correct |
38 ms |
3704 KB |
Output is correct |
9 |
Correct |
37 ms |
3704 KB |
Output is correct |
10 |
Correct |
37 ms |
3448 KB |
Output is correct |
11 |
Correct |
37 ms |
3448 KB |
Output is correct |
12 |
Correct |
37 ms |
3448 KB |
Output is correct |
13 |
Correct |
5 ms |
632 KB |
Output is correct |
14 |
Correct |
5 ms |
632 KB |
Output is correct |
15 |
Correct |
5 ms |
632 KB |
Output is correct |
16 |
Correct |
5 ms |
632 KB |
Output is correct |
17 |
Correct |
5 ms |
632 KB |
Output is correct |
18 |
Correct |
5 ms |
632 KB |
Output is correct |
19 |
Correct |
40 ms |
3480 KB |
Output is correct |
20 |
Correct |
41 ms |
3448 KB |
Output is correct |
21 |
Correct |
37 ms |
3452 KB |
Output is correct |
22 |
Correct |
45 ms |
3448 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
6 ms |
760 KB |
Output is correct |
2 |
Correct |
5 ms |
632 KB |
Output is correct |
3 |
Correct |
6 ms |
760 KB |
Output is correct |
4 |
Correct |
6 ms |
760 KB |
Output is correct |
5 |
Correct |
6 ms |
632 KB |
Output is correct |
6 |
Correct |
5 ms |
632 KB |
Output is correct |
7 |
Correct |
5 ms |
632 KB |
Output is correct |
8 |
Correct |
5 ms |
632 KB |
Output is correct |
9 |
Correct |
6 ms |
636 KB |
Output is correct |
10 |
Correct |
6 ms |
760 KB |
Output is correct |
11 |
Correct |
6 ms |
620 KB |
Output is correct |
12 |
Correct |
6 ms |
760 KB |
Output is correct |
13 |
Correct |
6 ms |
632 KB |
Output is correct |
14 |
Correct |
6 ms |
632 KB |
Output is correct |
15 |
Correct |
6 ms |
632 KB |
Output is correct |
16 |
Correct |
7 ms |
760 KB |
Output is correct |
17 |
Correct |
37 ms |
3448 KB |
Output is correct |
18 |
Correct |
39 ms |
3576 KB |
Output is correct |
19 |
Correct |
41 ms |
3448 KB |
Output is correct |
20 |
Correct |
7 ms |
760 KB |
Output is correct |
21 |
Correct |
6 ms |
760 KB |
Output is correct |
22 |
Correct |
6 ms |
760 KB |
Output is correct |
23 |
Correct |
6 ms |
632 KB |
Output is correct |
24 |
Correct |
5 ms |
632 KB |
Output is correct |
25 |
Correct |
38 ms |
3704 KB |
Output is correct |
26 |
Correct |
40 ms |
3704 KB |
Output is correct |
27 |
Correct |
39 ms |
3424 KB |
Output is correct |
28 |
Correct |
40 ms |
3540 KB |
Output is correct |
29 |
Correct |
52 ms |
3424 KB |
Output is correct |
30 |
Correct |
40 ms |
3448 KB |
Output is correct |
31 |
Correct |
6 ms |
760 KB |
Output is correct |
32 |
Correct |
5 ms |
632 KB |
Output is correct |
33 |
Correct |
31 ms |
2680 KB |
Output is correct |
34 |
Correct |
5 ms |
632 KB |
Output is correct |
35 |
Correct |
38 ms |
3448 KB |
Output is correct |
36 |
Correct |
5 ms |
632 KB |
Output is correct |
37 |
Correct |
5 ms |
632 KB |
Output is correct |
38 |
Correct |
38 ms |
3704 KB |
Output is correct |
39 |
Correct |
37 ms |
3704 KB |
Output is correct |
40 |
Correct |
37 ms |
3448 KB |
Output is correct |
41 |
Correct |
37 ms |
3448 KB |
Output is correct |
42 |
Correct |
37 ms |
3448 KB |
Output is correct |
43 |
Correct |
5 ms |
632 KB |
Output is correct |
44 |
Correct |
5 ms |
632 KB |
Output is correct |
45 |
Correct |
5 ms |
632 KB |
Output is correct |
46 |
Correct |
5 ms |
632 KB |
Output is correct |
47 |
Correct |
5 ms |
632 KB |
Output is correct |
48 |
Correct |
5 ms |
632 KB |
Output is correct |
49 |
Correct |
40 ms |
3480 KB |
Output is correct |
50 |
Correct |
41 ms |
3448 KB |
Output is correct |
51 |
Correct |
37 ms |
3452 KB |
Output is correct |
52 |
Correct |
45 ms |
3448 KB |
Output is correct |
53 |
Correct |
41 ms |
3448 KB |
Output is correct |
54 |
Correct |
39 ms |
3452 KB |
Output is correct |
55 |
Correct |
50 ms |
3448 KB |
Output is correct |
56 |
Correct |
6 ms |
632 KB |
Output is correct |
57 |
Correct |
6 ms |
632 KB |
Output is correct |
58 |
Correct |
35 ms |
2808 KB |
Output is correct |
59 |
Correct |
38 ms |
2680 KB |
Output is correct |
60 |
Correct |
35 ms |
2680 KB |
Output is correct |
61 |
Correct |
34 ms |
2684 KB |
Output is correct |
62 |
Correct |
35 ms |
2680 KB |
Output is correct |
63 |
Correct |
36 ms |
2756 KB |
Output is correct |
64 |
Correct |
41 ms |
3316 KB |
Output is correct |
65 |
Correct |
39 ms |
3324 KB |
Output is correct |
66 |
Correct |
39 ms |
3328 KB |
Output is correct |
67 |
Correct |
36 ms |
3316 KB |
Output is correct |
68 |
Correct |
39 ms |
3756 KB |
Output is correct |
69 |
Correct |
45 ms |
3704 KB |
Output is correct |
70 |
Correct |
40 ms |
3448 KB |
Output is correct |
71 |
Correct |
41 ms |
3452 KB |
Output is correct |
72 |
Correct |
48 ms |
3448 KB |
Output is correct |
73 |
Correct |
40 ms |
3448 KB |
Output is correct |
74 |
Correct |
40 ms |
3452 KB |
Output is correct |