Commented code to explain algorithms in 190 and 191

leetcode/README.md

@@ -32,6 +32,7 @@ LeetCode
 |169|[Majority Element](https://leetcode.com/problems/majority-element/) | [C](./src/169.c)|Easy|
 |173|[Binary Search Tree Iterator](https://leetcode.com/problems/binary-search-tree-iterator/) | [C](./src/173.c)|Medium|
 |190|[Reverse Bits](https://leetcode.com/problems/reverse-bits/) | [C](./src/190.c)|Easy|
+|191|[Number of 1 Bits](https://leetcode.com/problems/number-of-1-bits/) | [C](./src/191.c)|Easy|
 |203|[Remove Linked List Elements](https://leetcode.com/problems/remove-linked-list-elements/) | [C](./src/203.c)|Easy|
 |206|[Reverse Linked List](https://leetcode.com/problems/reverse-linked-list/) | [C](./src/206.c)|Easy|
 |215|[Kth Largest Element in an Array](https://leetcode.com/problems/kth-largest-element-in-an-array/) | [C](./src/215.c)|Medium|
@@ -47,7 +48,6 @@ LeetCode
 |389|[Find the Difference](https://leetcode.com/problems/find-the-difference/) | [C](./src/389.c)|Easy|
 |404|[Sum of Left Leaves](https://leetcode.com/problems/sum-of-left-leaves/) | [C](./src/404.c)|Easy|
 |442|[Find All Duplicates in an Array](https://leetcode.com/problems/find-all-duplicates-in-an-array/) | [C](./src/442.c)|Medium|
-|461|[Hamming Distance](https://leetcode.com/problems/hamming-distance/) | [C](./src/461.c)|Easy|
 |509|[Fibonacci Number](https://leetcode.com/problems/fibonacci-number/) | [C](./src/509.c)|Easy|
 |520|[Detect Capital](https://leetcode.com/problems/detect-capital/) | [C](./src/520.c)|Easy|
 |561|[Array Partition I](https://leetcode.com/problems/array-partition-i/) | [C](./src/561.c)|Easy|

leetcode/src/190.c

@@ -1,10 +1,13 @@
 uint32_t reverseBits(uint32_t n) {
     uint TotalBits = 32;
-    uint32_t reverse_int = 0;
+    uint32_t reverse_int = 0;   //stored in memory as 32 bits, each bit valued 0
     uint i;
     for(i = 0; i < TotalBits; i++) {
-        if((n & (UINT32_C(1) << i)))
-           reverse_int = reverse_int | (UINT32_C(1) << (TotalBits - 1 - i));
+        if((n & (UINT32_C(1) << i))) //if the bit on the ith position of 32 bit input is 1, then proceed
+                                     //Further note the use of UINT32_C to convert 1 to unsigned 32 bit int, since just 1 is treated as int which cannot be shifted left more than 30 times
+           reverse_int = reverse_int | (UINT32_C(1) << (TotalBits - 1 - i));    //Convert the ith bit from the end in reverse_int from 0 to 1, if ith bit from beginning in n is 1
+                                                                                //This is achieved by using bitwise OR on reverse_int (where ith bit from end is currently 0) and 
+                                                                                //1 shifted left 31 - i bits (to ith bit from the end) 
     }
     return reverse_int;
 }

leetcode/src/191.c

@@ -0,0 +1,10 @@
+int hammingWeight(uint32_t n) {
+    int TotalBits = 32;
+    int i, weight = 0;
+    for(i = 0; i < TotalBits; i++) {
+        if(n & (UINT32_C(1) << i))  //if the bit on the ith position of 32 bit input is 1, then proceed
+                                    //Further note the use of UINT32_C to convert 1 to unsigned 32 bit int, as just 1 is treated as int which cannot be shifted left more than 30 times
+            weight += 1;
+    }
+    return weight;
+}

leetcode/src/461.c

@@ -1,10 +0,0 @@
-int hammingDistance(int x, int y){
-    int difference = x ^ y;
-    int TotalBits = sizeof(difference)*8;
-    int i, distance = 0;
-    for(i = 0; i < TotalBits; i++) {
-        if(difference & (UINT32_C(1) << i))
-            distance += 1;
-    }   
-    return distance;
-}