Added 1165C - Good String

1151D - Stas and the queue at the buffet

@@ -0,0 +1,46 @@
+    #include<bits/stdc++.h>
+    #include<functional>
+    #include <ext/pb_ds/assoc_container.hpp>
+    #include <ext/pb_ds/tree_policy.hpp>
+
+
+    using namespace __gnu_pbds;
+    using namespace std;
+    typedef long long unsigned llu;
+    typedef long long ll;
+    typedef pair<ll, ll> ii;
+    typedef vector<ll> vl;
+
+    //use as vector<ii> v;
+    #define ff(a,b) for(ll i=a; i<b;i++)
+    #define MAX INT_MAX 
+    #define trace(x) cerr<<#x<<": "<<x<<" "<<'\n';
+    #define pb push_back
+    #define pob pop_back
+    #define mp make_pair
+    int main()
+    {
+        ios_base::sync_with_stdio(false);
+        cin.tie(NULL);
+    ll n;ll ans=0;
+    cin>>n;
+    //int ar[100005];
+    int a[100005];
+    int b[100005];
+    vector < pair <int,int> > v;
+    for(int i=0;i<n;i++)
+    {
+    	cin>>a[i]>>b[i];
+    	ans+=b[i]*n-a[i];
+    	v.pb(mp(a[i]-b[i],i));
+    }
+    sort(v.begin(),v.end());
+
+
+
+    for(int i=0;i<n;i++)
+    	ans+=((n-i)*v[i].first);
+
+    cout<<ans;
+    return 0;
+    }

1165C - Good String

@@ -0,0 +1,44 @@
+#include<bits/stdc++.h>
+#include<functional>
+#include <ext/pb_ds/assoc_container.hpp>
+#include <ext/pb_ds/tree_policy.hpp>
+
+
+using namespace __gnu_pbds;
+using namespace std;
+typedef long long unsigned llu;
+typedef long long ll;
+typedef pair<ll, ll> ii;
+typedef vector<ll> vl;
+
+//use as vector<ii> v;
+#define ff(a,b) for(ll i=a; i<b;i++)
+#define MAX INT_MAX 
+#define trace(x) cerr<<#x<<": "<<x<<" "<<'\n';
+#define pb push_back
+#define pob pop_back
+
+
+int main()
+{
+    ios_base::sync_with_stdio(false);
+    cin.tie(NULL);
+    cout.tie(NULL);
+    int n;
+    string ar,ans="";
+    cin>>n;
+    cin>>ar;
+    int len=ar.length()-1;
+    for(int i=0;i<len;i++)
+    {  // trace(i);
+        if(ar[i]!=ar[i+1])
+        {
+            ans+=ar[i];
+            ans+=ar[i+1];
+            i++;
+        }   
+    }
+cout<<ar.length()-ans.length()<<'\n';
+cout<<ans<<'\n';
+return 0;
+}