7.29

Author: huangyt39

3.py

@@ -0,0 +1,20 @@
+class Solution:
+    """
+    @param: : An integer
+    @param: : An integer
+    @return: An integer denote the count of digit k in 1..n
+    """
+
+    def digitCounts(self, n, k):
+        # write your code here
+        result = 0
+        if(k == 0): result += 1
+        for i in range(int(n + 1)):
+          while i > 0:
+            if i % 10 == k:
+              result += 1
+            i //= 10
+        return result
+
+print(Solution.digitCounts(1, 19, 0))
+

4.py

@@ -0,0 +1,26 @@
+class Solution:
+    """
+    @param n: An integer
+    @return: the nth prime number as description.
+    """
+    def nthUglyNumber(self, n):
+        # write your code here
+      list = [1]
+      if n == 1: return 1;
+      for num in range(n - 1):
+        for i in list:
+          if i*2 > list[-1]:
+            min2 = i*2
+            break
+        for i in list:
+          if i*3 > list[-1]:
+            min3 = i*3
+            break
+        for i in list:
+          if i*5 > list[-1]:
+            min5 = i*5
+            break
+        list.append(min(min2, min3, min5))
+      return list[-1]
+
+print(Solution.nthUglyNumber(9, 9));