delete pics to save space

7.2104.cpp

@@ -0,0 +1,52 @@
+#include<cstdio>
+#include<iostream>
+#include<cstring>
+#include<algorithm>
+using namespace std;
+const int maxn=100005;
+const int maxmem=2*(maxn*2+17*maxn);
+int n,m,T,a[maxn],b[maxn],rt[maxn*2],lc[maxmem],rc[maxmem],cnt[maxmem],ncnt;
+void build(int &o,int L,int R)
+{
+	o=++ncnt;
+	if(L==R) return;
+	int M=(L+R)>>1;
+	build(lc[o],L,M);
+	build(rc[o],M+1,R);
+}
+int modify(int o,int L,int R,int val)
+{
+	int no=++ncnt;
+	lc[no]=lc[o]; rc[no]=rc[o]; cnt[no]=cnt[o]+1;
+	if(L==R) return no;
+	int M=(L+R)>>1;
+	if(val<=M) lc[no]=modify(lc[o],L,M,val);
+	else rc[no]=modify(rc[o],M+1,R,val);
+	return no;
+}
+int query(int lrt,int rrt,int L,int R,int k)
+{
+	int M=(L+R)>>1,x=cnt[lc[rrt]]-cnt[lc[lrt]];
+	if(L==R) return L;
+	if(x>=k) return query(lc[lrt],lc[rrt],L,M,k);
+	else return query(rc[lrt],rc[rrt],M+1,R,k-x);
+}
+int main()
+{
+#ifdef local
+	freopen("pro.in","r",stdin);
+#endif
+	ios::sync_with_stdio(0);
+	cin>>n>>m;
+	for(int i=1;i<=n;i++) { cin>>a[i]; b[i]=a[i]; }
+	sort(b+1,b+1+n);
+	T=unique(b+1,b+1+n)-(b+1);
+	build(rt[0],1,T);
+	for(int i=1;i<=n;i++) rt[i]=modify(rt[i-1],1,T,lower_bound(b+1,b+1+n,a[i])-b);
+	for(int i=1;i<=m;i++)
+	{
+		int L,R,k; cin>>L>>R>>k;
+		cout<<b[query(rt[L-1],rt[R],1,T,k)]<<'\n';
+	}
+	return 0;
+}