modify code

Author: algorithmzuo

src/class47/Code03_DinicAlgorithm.java

@@ -90,6 +90,9 @@ private int dfs(int s, int t, int r) {
 if (s == t || r == 0) {
 return r;
 }
+if (depth[s] >= depth[t]) {
+return 0;
+}
 int f = 0;
 int flow = 0;
 // s点从哪条边开始试 -> cur[s]