diff --git a/CSP-Training/5/4-tour.cpp b/CSP-Training/5/4-tour.cpp
new file mode 100644
index 0000000..d11c472
--- /dev/null
+++ b/CSP-Training/5/4-tour.cpp
@@ -0,0 +1,60 @@
+//最昂贵的旅行
+#include <cstdio>
+#include <cstring>
+#include <iostream>
+using namespace std;
+int dijkstra(int n);
+int map[100][100]; //编号0~n-1
+int main()
+{
+    int n, source, dest, cost;
+    scanf("%d", &n);
+    memset(map, 0x7f, sizeof(map));
+    for (int i = 0; i < n - 1; i++)
+    {
+        scanf("%d %d %d", &source, &dest, &cost);
+        map[source][dest] = cost;
+        map[dest][source] = cost;
+    }
+    cout << dijkstra(n);
+    return 0;
+}
+int dijkstra(int n) //Source=0
+{
+    bool visited[101];
+    int dist[101], maxDist = -1;
+    memset(visited, false, sizeof(visited));
+    memset(dist, 0x7f, sizeof(dist));
+    dist[0] = 0;
+    for (int i = 0; i < n; i++)
+    {
+        int u = 100;
+        for (int j = 0; j < n; j++)
+        {
+            if (visited[j] == false && dist[j] < dist[u])
+            {
+                u = j;
+            }
+        }
+        if (u == 100)
+        {
+            break;
+        }
+        visited[u] = true;
+        for (int j = 0; j < n; j++)
+        {
+            if (visited[j] == false && dist[j] > map[u][j] + dist[u])
+            {
+                dist[j] = map[u][j] + dist[u];
+            }
+        }
+    }
+    for (int i = 0; i < n; i++)
+    {
+        if (dist[i] > maxDist)
+        {
+            maxDist = dist[i];
+        }
+    }
+    return maxDist;
+}
\ No newline at end of file