Deque Problem

Author: rahulbordoloi

HackerRank Practice/deque.cpp

@@ -0,0 +1,87 @@
+#include <bits/stdc++.h>
+
+#define fast ios_base::sync_with_stdio(0);cin.tie(NULL);cout.tie(NULL)
+#define f(i,a,b) for(auto i=a;i<b;i++)
+#define fi(i,a,b,x) for(auto i=a;i<b;i=i+x)
+#define fe(i,a,b) for(auto i=a;i<=b;i++)
+#define fr(i,a,b) for(auto i=a;i>=b;i--)
+#define loop(i, a) for(auto i=a.begin();i!=a.end();i++)
+#define endl '\n'
+#define sp '\t'
+#define ll long long int
+#define ff first
+#define ss second
+#define pb push_back
+#define mp make_pair
+#define all(x) x.begin(), x.end()
+#define clr(x) memset(x, 0, sizeof(x))
+#define sortall(x) sort(all(x))
+#define mod 1000000007
+#define PI 3.1415926535897932384626
+#define deb(x) cout<<#x<<"="<<x<<endl
+#define deb2(x, y) cout<<#x<<" = "<<x<<","<<#y<<" = "<<y<<endl
+
+using namespace std;
+
+template <typename T>
+void print(vector<T>& a, char sep)
+{
+    for(auto i : a) { cout<<i<<sep; }
+}
+
+ll mod_opr(ll num)
+{
+    return (num + mod) % mod;
+}
+
+template <typename T>
+bool compare(T x, T y)
+{
+    return x > y ? true : false;
+}
+
+void printKMax(int arr[], int n, int k){
+    
+    deque<int> de(k);
+    int i;
+    f(i, 0, k){
+        while(!de.empty() && arr[i] >= arr[de.back()])
+            de.pop_back();
+        de.push_back(i);
+    }
+    for(;i<n;i++){
+        cout<<arr[de.front()]<<" ";
+        while((!de.empty()) && (de.front() <= i - k))
+            de.pop_front();
+        while((!de.empty()) && (arr[i] >= arr[de.back()]))
+            de.pop_back();
+        de.push_back(i);
+    }
+    cout<<arr[de.front()]<<endl;
+}
+
+int main()
+{
+
+    // ONLINE_JUDGE
+    #ifndef rahulbordoloi
+        freopen("input.txt", "r", stdin);
+        // freopen("output.txt", "w", stdin);
+    #endif
+
+    // Code
+    fast;
+    int tc;
+    cin>>tc;
+	while(tc--){
+		int n, k, i;
+    	cin>>n>>k;
+    	int arr[n];
+    	f(i,0,n) { cin>>arr[i]; }
+    	printKMax(arr, n, k);
+  	}
+
+    // cerr<<"TIME : "<<clock()<<endl;
+    return 0;
+
+}