Added range sum query and sum of a range [l,r] for segment tree!

Author: abhi211199

Data Structures/Segment Tree/range min query.cpp

@@ -0,0 +1,66 @@
+#include<bits/stdc++.h>
+#define ll long long;
+using namespace std;
+
+int s[100];
+int sn=INT_MIN;
+
+int build(int v[],int s[],int pos,int start,int end)
+{
+	if(start==end)
+		{s[pos]=v[start];
+			cout<<pos<<"#"<<s[pos]<<" ";
+			if(pos>sn)
+				sn=pos;
+			return s[pos];}
+			// cout<<pos<<" ";
+		int mid=(start+end)/2;
+		
+		s[pos]=min(build(v,s,2*pos+1,start,mid),
+		build(v,s,2*pos+2,mid+1,end));
+		if(pos>sn)
+				sn=pos;
+		cout<<pos<<"#"<<s[pos]<<" ";
+		return s[pos];
+}
+
+int buildtree(int v[],int n)
+{
+	// cout<<v.size()-1;
+	build(v,s,0,0,n-1);
+	return 0;
+}
+
+void disp(int n)
+{
+	// vector<int>::iterator i;
+	int i=0;
+	for(i=0;i!=2*n+5;i++)
+	// for(i=0;i<sizeof(t)/sizeof(int);i++)
+		cout<<s[i]<<" ";
+}
+
+int rmq(int qlow,int qhigh,int high,int low,int pos)
+{
+	if(qlow<=low&&qhigh>=high)//the query overlaps the segment tree nodes
+		return s[pos];
+	if(qlow>high||qhigh<low)//no overlap
+		return INT_MAX;
+	int mid=(high+low)/2;
+	return min(rmq(qlow,qhigh,mid,low,2*pos+1),rmq(qlow,qhigh,high,mid+1,2*pos+2));
+}
+
+int main()
+{
+	int n=0,i=0,a=0,v[100],qlow=0,qhigh=0;
+	cin>>n;
+	for(i=0;i<n;i++)
+	cin>>v[i];
+	buildtree(v,n);
+	cout<<endl;
+	disp(n);
+	cout<<endl;
+	cin>>qlow>>qhigh;
+	cout<<rmq(qlow,qhigh,n-1,0,0);
+	return 0;
+}

Data Structures/Segment Tree/sum of a range.cpp

@@ -0,0 +1,84 @@
+#include<bits/stdc++.h>
+#define ll long long;
+using namespace std;
+
+int s[100];
+
+int build(int v[],int s[],int pos,int start,int end)
+{
+	if(start==end)
+		{s[pos]=v[start];
+			cout<<pos<<"#"<<s[pos]<<" ";
+			return s[pos];}
+			// cout<<pos<<" ";
+		int mid=(start+end)/2;
+		
+		s[pos]=(build(v,s,2*pos+1,start,mid)+
+		build(v,s,2*pos+2,mid+1,end));
+		cout<<pos<<"#"<<s[pos]<<" ";
+		return s[pos];
+}
+
+int buildtree(int v[],int n)
+{
+	// cout<<v.size()-1;
+	build(v,s,0,0,n-1);
+	return 0;
+}
+
+void disp(int n)
+{
+	// vector<int>::iterator i;
+	int i=0;
+	for(i=0;i!=2*n+5;i++)
+	// for(i=0;i<sizeof(t)/sizeof(int);i++)
+		cout<<s[i]<<" ";
+}
+
+int sum(int qlow,int qhigh,int high,int low,int pos)
+{
+	if(qlow<=low&&qhigh>=high)//the query overlaps the segment tree nodes
+		return s[pos];
+	if(qlow>high||qhigh<low)//no overlap
+		return 0;
+	int mid=(high+low)/2;
+	return (sum(qlow,qhigh,mid,low,2*pos+1)+sum(qlow,qhigh,high,mid+1,2*pos+2));
+}
+
+void updatetree(int d,int i,int low,int high,int pos)
+{
+	if(i<low||i>high)
+		return;
+	s[pos]+=d;
+	if(low!=high){
+	int mid=(low+high)/2;
+	updatetree(d,i,low,mid,2*pos+1);
+	updatetree(d,i,mid+1,high,2*pos+2);
+	}
+}
+
+int update(int n,int a,int b)
+{
+	updatetree(a,b,0,n-1,0);
+	return 0;
+}
+
+int main()
+{
+	int n=0,i=0,a=0,v[100],qlow=0,qhigh=0,b=0;
+	cin>>n;
+	for(i=0;i<n;i++)
+	cin>>v[i];
+	buildtree(v,n);
+	cout<<endl;
+	disp(n);
+	cout<<endl;
+	cin>>qlow>>qhigh;
+	cout<<sum(qlow,qhigh,n-1,0,0);
+	cout<<"\nenter new value and index(0th based) to update!";
+	cin>>a>>b;
+	update(n,a-v[b],b);
+	cout<<endl;
+	disp(n);
+	return 0;
+}