P1938 [USACO09NOV]Job Hunt S

R53992295

Luogu/problem/P1938/P1938.cpp

@@ -0,0 +1,40 @@
+#include <bits/stdc++.h>
+
+using namespace std;
+
+int d, p, c, f, s, t, dist[505], x;
+
+struct node {
+    int u, v, w;
+} g[1005];
+
+int main() {
+    cin >> d >> p >> c >> f >> s;
+    for (int i = 1; i <= p; i++) {
+        cin >> g[i].u >> g[i].v;
+        g[i].w = -d;
+    }
+    for (int i = p + 1; i <= p + f; i++) {
+        cin >> g[i].u >> g[i].v >> t;
+        g[i].w = t - d;
+    }
+    memset(dist, 0x3f, sizeof(dist));
+    dist[s] = 0;
+    for (int i = 1; i <= c; i++) {
+        for (int j = 1; j <= p + f; j++) {
+            dist[g[j].v] = min(dist[g[j].v], dist[g[j].u] + g[j].w);
+        }
+    }
+    for (int i = 1; i <= p + f; i++) {
+        if (dist[g[i].v] > dist[g[i].u] + g[i].w) {
+            cout << -1 << endl;
+            exit(0);
+        }
+    }
+    dist[0] = 0x3f3f3f3f;
+    for (int i = 1; i <= c; i++) {
+        x = dist[i] < dist[x] ? i : x;
+    }
+    cout << d - dist[x] << endl;
+    return 0;
+}