init

3D.cpp

@@ -0,0 +1,50 @@
+#include <iostream>
+
+using namespace std;
+
+long long x[20005];
+long long y[20005];
+long long D[20005];
+bool visited[20005];
+
+int main() {
+    int n;
+    cin >> n;
+    for (int i = 1; i <= n; i++) {
+        cin >> x[i] >> y[i];
+    }
+    int s, t;
+    cin >> s >> t;
+    long long INF = 1000000000000000000LL;
+    for (int i = 1; i <= n; i++) {
+        D[i] = INF;
+        visited[i] = false;
+    }
+    D[s] = 0;
+    for (int i = 1; i <= n; i++) {
+        int u = -1;
+        long long min_d = INF;
+        for (int j = 1; j <= n; j++) {
+            if (visited[j] == false && D[j] < min_d) {
+                min_d = D[j];
+                u = j;
+            }
+        }
+        if (u == -1 || u == t || D[u] == INF) {
+            break;
+        }
+        visited[u] = true;
+        for (int v = 1; v <= n; v++) {
+            if (visited[v] == false) {
+                long long dx = x[u] - x[v];
+                long long dy = y[u] - y[v];
+                long long cost = D[u] + dx * dx + dy * dy;           
+                if (cost < D[v]) {
+                    D[v] = cost;
+                }
+            }
+        }
+    }
+    cout << D[t] << "\n";
+    return 0;
+}