codechef GOODBINSTR

Author: Pankajcoder1

Codechef/GOODBINSTR.cpp

@@ -0,0 +1,90 @@
+/*
+    written by Pankaj Kumar.
+    country:-INDIA
+*/
+#include <bits/stdc++.h>
+using namespace std;
+typedef long long ll;
+
+
+int solve(){
+    string s;
+    cin>>s;
+    int n=s.size();
+    int count=0;
+
+    int oneZero=0,zeroOne=0;
+    for(int i=1;i<n;i++){
+        if(s[i-1]=='0' && s[i]=='1'){
+            zeroOne++;
+        }
+        else if(s[i-1]=='1' && s[i]=='0'){
+            oneZero++;
+        }
+    }
+    for(int i=0;i<n;i++){
+        int tempZeroOne=zeroOne,tempOneZero=oneZero;
+        if(i-1>=0){
+            if(s[i-1]=='1'){
+                // 11 -> 10
+                if(s[i]=='1'){
+                    tempOneZero++;
+                }
+                // 10 -> 11
+                else{
+                    tempOneZero--;
+                }
+            }
+            else{
+                // 01 -> 00
+                if (s[i] == '1')
+                {
+                    tempZeroOne--;
+                }
+                // 00 -> 01
+                else
+                {
+                    tempZeroOne++;
+                }
+            }
+        }
+        if(i+1<n){
+            if(s[i]=='1'){
+                // 11 -> 01
+                if(s[i+1]=='1'){
+                    tempZeroOne++;
+                }
+                //  10 -> 00
+                else{
+                    tempOneZero--;
+                }
+            }
+            else{
+                // 01 -> 11
+                if (s[i + 1] == '1')
+                {
+                    tempZeroOne--;
+                }
+                //  00 -> 10
+                else
+                {
+                    tempOneZero++;
+                }
+            }
+        }
+        if(tempZeroOne==tempOneZero){
+            count++;
+        }
+    }
+    cout<<count<<endl;
+    return 0;
+}
+int main()
+{
+    int testCase=1;
+    cin>>testCase;
+    while(testCase--){
+        solve();
+    }
+    return 0;
+}