add 172 folder & cpp, add 190 folder & cpp, add 434 folder & cpp

Author: zouwx2cs

solution/172.Factorial Trailing Zeroes/Solution.cpp

@@ -0,0 +1,9 @@
+class Solution {
+public:
+    int trailingZeroes(int n) {
+        int cnt5 = 0 ;
+        for (long long i = 5; i <= n; i *= 5)
+            cnt5 += n/i ;
+        return cnt5 ;
+    }
+};

solution/190.Reverse Bits/Solution.cpp

@@ -0,0 +1,16 @@
+class Solution {
+public:
+    uint32_t reverseBits(uint32_t n) {
+        uint32_t res = 0 ;
+        uint32_t tmp = 1 << 31 ;
+        while (n)
+        {
+            if (n&1)
+                res |= tmp ;
+            tmp >>= 1 ;
+            n >>= 1 ;
+        }
+        
+        return res ;
+    }
+};

solution/434.Number of Segments in a String/Solution.cpp

@@ -0,0 +1,13 @@
+class Solution {
+public:
+    int countSegments(string s) {
+        if (s.length() < 1)
+            return 0 ;
+        
+        int cnt = isspace(s[0])? 0: 1 ;
+        for (int i = 1; i < s.length(); ++i)
+            if (!isspace(s[i]) && isspace(s[i-1]))
+                ++cnt ;
+        return cnt ;
+    }
+};