字典序排列的实现

1 files changed, 29 insertions, 0 deletions

diff --git a/algo/lexicographic_order.py b/algo/lexicographic_order.py
new file mode 100644
index 0000000..f2a6631
--- /dev/null
+++ b/algo/lexicographic_order.py
@@ -0,0 +1,29 @@
+
+
+
+def lexicoal_permute(seq):
+
+    n = len(seq)
+    max_x = -1
+    seq.sort()
+    print(seq)
+    while True:
+        for i in range(n-1):
+            if seq[i] < seq[i+1]:
+                max_x = i
+        if max_x == -1:
+            break
+        max_y = -1
+        for i in range(n):
+            if seq[i] > seq[max_x]:
+                max_y = i
+        # swap
+        seq[max_x], seq[max_y] = seq[max_y], seq[max_x]
+        # reverse
+        seq[max_x+1:] = seq[n-1:max_x:-1]
+        max_x = -1
+        print(seq)
+
+
+if __name__ == '__main__':
+    lexicoal_permute(['a', 'c', 'b'])