#include <bits/stdc++.h>
using namespace std;
const int N = 2005;
const int L = 100005;
const long long INF = 1e18;
struct Edge {
int w, to, id;
};
struct F {
long long w; int x, y;
F() { w = INF, x = y = 0; }
F(long w, int x, int y) : w(w), x(x), y(y) {}
void dbg() { cout << "#F " << w << ' ' << x << ' ' << y << '\n';}
};
int n, m, l, q;
int arr[L];
F f[N][N][4];
vector<Edge> G[N];
struct SegmentTree {
struct Node { F f[4]; };
Node T[L << 2];
#define mid ((l + r) >> 1)
Node merge(Node &x, Node &y, Node &z) {
Node ret;
for (int i = 0; i < 4; ++i) {
for (int j = 0; j < 4; ++j) {
for (int k = 0; k < 4; ++k) {
long long tmp = x.f[i].w + y.f[j].w + z.f[k].w;
if (x.f[i].y == z.f[k].x || z.f[k].y == y.f[j].x) continue;
for (int l = 0; l < 4; ++l) {
if (ret.f[l].w > tmp) {
for (int t = 3; t > l; --t) ret.f[t] = ret.f[t - 1];
int L = x.f[i].x; if (L == 0) L = z.f[k].x;
int R = y.f[j].y; if (R == 0) R = z.f[k].y;
ret.f[l] = F(tmp, L, R);
break;
}
}
}
}
}
return ret;
}
void modify(int i, int l, int r) {
Node tmp;
for (int i = 0; i < 4; ++i) {
tmp.f[i] = f[arr[mid]][arr[mid + 1]][i];
}
T[i] = merge(T[i << 1], T[i << 1 | 1], tmp);
}
void build(int i, int l, int r) {
if (l == r) { T[i].f[0].w = 0; return; }
build(i << 1, l, mid);
build(i << 1 | 1, mid + 1, r);
modify(i, l, r);
}
void upd(int i, int l, int r, int p, int x) {
if (l == r) { arr[l] = x; return; }
if (mid >= p) upd(i << 1, l, mid, p, x);
else upd(i << 1 | 1, mid + 1, r, p, x);
modify(i, l, r);
}
#undef mid
} IT;
struct Data {
long long w; int u, x;
bool operator < (const Data& rhs) const {
return w > rhs.w;
}
};
void cal(int r) {
f[r][r][0].w = 0;
priority_queue<Data> pq;
for (auto i : G[r]) {
int w = i.w, u = i.to, id = i.id;
for (int j = 0; j < 4; ++j) {
if (f[r][u][j].w > w) {
for (int k = 3; k > j; --k) f[r][u][k] = f[r][u][k - 1];
f[r][u][j] = F(0LL + w, id, id), pq.push({0LL + w, u, j}); break;
}
}
}
while (pq.size()) {
long long w = pq.top().w;
int u = pq.top().u, x = pq.top().x;
pq.pop();
if (f[r][u][x].w != w) continue;
for (auto i : G[u]) {
int w = i.w, v = i.to, id = i.id;
for (int j = 0; j < 4; ++j) {
if (f[r][u][x].y == id) continue;
if (f[r][v][j].w > f[r][u][x].w + w) {
for (int k = 3; k > j; --k) f[r][v][k] = f[r][v][k - 1];
f[r][v][j] = F(f[r][u][x].w + w, f[r][u][x].x, id);
pq.push({f[r][v][j].w, v, j}); break;
}
}
}
}
}
int main() {
ios::sync_with_stdio(false);
cin >> n >> m >> q >> l;
for (int i = 1; i <= m; ++i) {
int u, v, w; cin >> u >> v >> w;
G[u].push_back({w, v, i});
G[v].push_back({w, u, i});
}
for (int i = 1; i <= n; ++i) cal(i);
for (int i = 1; i <= l; ++i) cin >> arr[i];
IT.build(1, 1, l);
while (q--) {
int p, x; cin >> p >> x;
IT.upd(1, 1, l, p, x);
long long res = IT.T[1].f[0].w;
cout << (res == INF ? -1 : res) << '\n';
}
}
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
223 ms |
277240 KB |
Output is correct |
2 |
Correct |
324 ms |
277352 KB |
Output is correct |
3 |
Correct |
229 ms |
277524 KB |
Output is correct |
4 |
Correct |
210 ms |
277524 KB |
Output is correct |
5 |
Incorrect |
220 ms |
277536 KB |
Output isn't correct |
6 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
223 ms |
277240 KB |
Output is correct |
2 |
Correct |
324 ms |
277352 KB |
Output is correct |
3 |
Correct |
229 ms |
277524 KB |
Output is correct |
4 |
Correct |
210 ms |
277524 KB |
Output is correct |
5 |
Incorrect |
220 ms |
277536 KB |
Output isn't correct |
6 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
223 ms |
277240 KB |
Output is correct |
2 |
Correct |
324 ms |
277352 KB |
Output is correct |
3 |
Correct |
229 ms |
277524 KB |
Output is correct |
4 |
Correct |
210 ms |
277524 KB |
Output is correct |
5 |
Incorrect |
220 ms |
277536 KB |
Output isn't correct |
6 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
223 ms |
277240 KB |
Output is correct |
2 |
Correct |
324 ms |
277352 KB |
Output is correct |
3 |
Correct |
229 ms |
277524 KB |
Output is correct |
4 |
Correct |
210 ms |
277524 KB |
Output is correct |
5 |
Incorrect |
220 ms |
277536 KB |
Output isn't correct |
6 |
Halted |
0 ms |
0 KB |
- |