save project

binary_search.py

+num = 1
+low = 0
+high = 9
 a = [1, 3, 5, 8, 11, 15, 17, 18, 20, 21]
 a = [1, 3, 5, 8, 11, 15, 17, 18, 20, 21]
-num=11
-mid = (low+high)//2
-if mid == num:
-    print(找到了)
-elif mid < guess:
-    low == mid+1
-else:
-    high == mid-1
+for i in range(3):
+    mid = (low+high)//2
+    if a[mid] == num:
+        print(a[mid])
+    elif mid < num:
+        low = mid+1
+    else :
+        high = mid-1