Implicit Segment Tree added

Author: zarif98sjs

Data Structure/33 ImplicitSegmentTree (Point Update,Range Query).cpp

@@ -0,0 +1,215 @@
+
+/** Which of the favors of your Lord will you deny ? **/
+
+#include<bits/stdc++.h>
+using namespace std;
+
+#define LL long long
+#define PII pair<int,int>
+#define PLL pair<LL,LL>
+#define F first
+#define S second
+
+#define ALL(x)      (x).begin(), (x).end()
+#define READ        freopen("alu.txt", "r", stdin)
+#define WRITE       freopen("vorta.txt", "w", stdout)
+
+#ifndef ONLINE_JUDGE
+#define DBG(x)      cout << __LINE__ << " says: " << #x << " = " << (x) << endl
+#else
+#define DBG(x)
+#define endl "\n"
+#endif
+
+template<class T1, class T2>
+ostream &operator <<(ostream &os, pair<T1,T2>&p);
+template <class T>
+ostream &operator <<(ostream &os, vector<T>&v);
+template <class T>
+ostream &operator <<(ostream &os, set<T>&v);
+
+inline void optimizeIO()
+{
+    ios_base::sync_with_stdio(false);
+    cin.tie(NULL);
+}
+
+const int nmax = 2e5+7;
+
+/**
+
+Implicit Segment Tree (Point Update , Range Query)
+==================================================
+1 based indexing
+
+**/
+
+struct Node
+{
+    int sum;
+    Node *left , *right;
+
+    Node() /// change here
+    {
+        sum = 0;
+        left = NULL;
+        right = NULL;
+    }
+};
+
+struct ImplicitSegmentTree
+{
+    int n;
+    Node *root;
+
+    ImplicitSegmentTree(int n)
+    {
+        this->n = n;
+        root = new Node();
+    }
+
+    void update(int updex,int val)
+    {
+        update(root,1,n,updex,val);
+    }
+
+    void update(Node* v,int start,int end,int updex,int val)
+    {
+        if(start==end)
+        {
+            v->sum += val;
+            return;
+        }
+
+        int mid = (start+end)>>1;
+
+        if(v->left==NULL) v->left = new Node();
+        if(v->right==NULL) v->right = new Node();
+
+        if(updex<=mid) update(v->left,start,mid,updex,val);
+        else update(v->right,mid+1,end,updex,val);
+
+        v->sum = v->left->sum + v->right->sum;
+    }
+
+    int query(int ql,int qr)
+    {
+        return query(root,1,n,ql,qr);
+    }
+
+    int query(Node *v,int start,int end,int ql,int qr)
+    {
+        if(v==NULL) return 0;
+
+        if(end<ql || start>qr) return 0;
+
+        if(start>=ql && end<=qr)
+        {
+            return v->sum;
+        }
+
+        int mid = (start+end)>>1;
+
+//        if(v->left==NULL) v->left = new Node();
+//        if(v->right==NULL) v->right = new Node();
+
+        /// query on both child
+        int p1 = query(v->left,start,mid,ql,qr);
+        int p2 = query(v->right,mid+1,end,ql,qr);
+
+        return p1+p2;
+    }
+};
+
+void solveTC()
+{
+    int n,q;
+//    cin>>n>>q;
+    scanf("%d %d",&n,&q);
+
+    int MX = 1e9+2;
+
+    ImplicitSegmentTree s(MX);
+
+    vector<int>v(n+1);
+
+    for(int i=1;i<=n;i++) scanf("%d",&v[i]);
+
+    for(int i=1;i<=n;i++) s.update(v[i],1);
+
+    while(q--)
+    {
+        char ch;
+        scanf(" %c ",&ch);
+
+        if(ch=='!')
+        {
+            int pos,new_val;
+            scanf("%d %d",&pos,&new_val);
+
+            s.update(v[pos],-1);
+            v[pos] = new_val;
+            s.update(v[pos],1);
+
+        }
+        else
+        {
+            int a,b;
+            scanf("%d %d",&a,&b);
+
+            int ans = s.query(a,b);
+            printf("%d\n",ans);
+        }
+    }
+}
+
+int32_t main()
+{
+    optimizeIO();
+
+    int tc = 1;
+//    cin>>tc;
+
+    while(tc--)
+    {
+        solveTC();
+    }
+
+    return 0;
+}
+
+/**
+
+**/
+
+template<class T1, class T2>
+ostream &operator <<(ostream &os, pair<T1,T2>&p)
+{
+    os<<"{"<<p.first<<", "<<p.second<<"} ";
+    return os;
+}
+template <class T>
+ostream &operator <<(ostream &os, vector<T>&v)
+{
+    os<<"[ ";
+    for(T i:v)
+    {
+        os<<i<<" " ;
+    }
+    os<<" ]";
+    return os;
+}
+
+template <class T>
+ostream &operator <<(ostream &os, set<T>&v)
+{
+    os<<"[ ";
+    for(T i:v)
+    {
+        os<<i<<" ";
+    }
+    os<<" ]";
+    return os;
+}
+
+