# luogu P1772 [ZJOI2006] 物流运输 （dp， 最短路）

https://www.luogu.com.cn/problem/P1772

f[i] = min(f[i], f[j] + cost[j + 1][i] * (i - j) + K);

#include<bits/stdc++.h>
using namespace std;
#define IOS ios::sync_with_stdio(false) ,cin.tie(0), cout.tie(0);
//#pragma GCC optimize(3,"Ofast","inline")
#define ll long long
#define PII pair<int, int>
//#define int long long
const int N = 1e5 + 5;
const int M = 5e5 + 5;
const int INF = 0x3f3f3f3f;
const ll LNF = 0x3f3f3f3f3f3f3f3f;
const int mod = 998244353;
const double PI = acos(-1.0);
struct Edge {
int u, v, w;
} eds[205];
struct Day {
int p, a, b;
}day[205];

int h[205], e[205 << 1], ne[205 << 1], w[205 << 1], idx;
bool st[205];

int dist[25]; int m;
ll cost[105][105], f[105];
void add( int a, int b, int c) {
e[idx] = b, ne[idx] = h[a], w[idx] = c, h[a] = idx ++;
}
int spfa() {
memset(dist, 0x3f, sizeof dist);
dist[1] = 0;
queue<int> q;
q.push(1); st[1] = 1;
while (q.size())
{
auto t = q.front();
q.pop();

st[t] = false;

for (int i = h[t]; i != -1; i = ne[i])
{
int j = e[i];
if (dist[j] > dist[t] + w[i])
{
dist[j] = dist[t] + w[i];
if (!st[j])
{
q.push(j);
st[j] = true;
}
}
}
}
return dist[m];
}
int main() {
IOS
int n, K, e, d; cin >> n >> m >> K >> e;
for ( int i = 1; i <= e; ++ i ) {
cin >> eds[i].u >> eds[i].v >> eds[i].w;
}
cin >> d;
for( int i = 1; i <= d; ++ i) {
int p, a, b; cin >> p >> a >> b;
day[i] = {p, a, b};
}
for ( int i = 1; i <= n; ++ i ) {
for ( int j = i; j <= n; ++ j ) {
memset(h, -1, sizeof h); memset(st, 0, sizeof st); idx = 0;

for (int k = 1; k <= d; ++ k) {
int p = day[k].p, a = day[k].a, b = day[k].b;
if( b < i || a > j ) {}
else {st[p] = 1; }
}

for ( int k = 1; k <= e; ++ k ) {
if(!st[eds[k].u] && !st[eds[k].v]) {
}
}
cost[i][j] = spfa();
}
}

for ( int i = 1; i <= 100; ++ i ) f[i] = 1e18;
f[0] = -K;
for ( int i = 1; i <= n; ++ i ) {
for ( int j = 0; j < i; ++ j ) {
f[i] = min(f[i], f[j] + cost[j + 1][i] * (i - j) + K);
// cout << j << " " << i << " " << f[i] << '\n';
}
}
cout << f[n] << '\n';
return 0;
}

posted @ 2022-09-26 18:09  qingyanng  阅读(23)  评论(0编辑  收藏  举报