From aa7720bdc6f8ea01978302bef05c7388e2d603d0 Mon Sep 17 00:00:00 2001
From: Chayan Das <110921638+Chayandas07@users.noreply.github.com>
Date: Mon, 26 Dec 2022 03:30:06 +0530
Subject: [PATCH] Create 26 December  Akku and Binary Numbers

26 December

Akku and Binary Numbers
---
 26 December  Akku and Binary Numbers | 61 ++++++++++++++++++++++++++++
 1 file changed, 61 insertions(+)
 create mode 100644 26 December  Akku and Binary Numbers

diff --git a/26 December  Akku and Binary Numbers b/26 December  Akku and Binary Numbers
new file mode 100644
index 00000000..03cf7d12
--- /dev/null
+++ b/26 December  Akku and Binary Numbers	
@@ -0,0 +1,61 @@
+class Solution{
+private:
+    long long cnts[3][64];
+public:
+    void precompute()
+    {
+        // build searching table
+        cnts[0][63] = cnts[1][63] = cnts[2][63] = 0ll;
+        
+        // Code Here
+        for (int i = 0; i < 63; i++) {
+            cnts[0][i] = i + 1;
+            
+            if (i < 2) {
+                cnts[1][i] = 0;
+            } else {
+                cnts[1][i] = i - 1 + cnts[1][i-1];
+            }
+            
+            if (i < 3) {
+                cnts[2][i] = 0;
+            } else {
+                cnts[2][i] = cnts[1][i-1] + cnts[2][i-1];
+            }
+        }
+    }
+    
+    long long solve(long long l, long long r){
+        // Code Here
+        long long res = 0;
+
+        if (l < 1 || r < l || r > 1000000000000000000) {
+            return -1;
+        }
+        
+        long long l_cnt = 0, r_cnt = 0;
+        
+        // [l, r] ~ (l-1, r]
+        l--;
+        
+        // searching all possible 3bits numbers from table
+        for (int i = 2; i >= 0; i--) {
+            if (l > 0) {
+                int cl = 63 - __builtin_clzll(l);
+                l_cnt += cnts[i][cl];
+                
+                l ^= 1ll << cl;
+            }
+            
+            if (r > 0) {
+                int cr = 63 - __builtin_clzll(r);
+                r_cnt += cnts[i][cr];
+                
+                r ^= 1ll << cr;
+            }
+        }
+        
+        return (r_cnt - l_cnt);
+    }
+    
+};