diff --git a/HDOJ/5919_dgutfly.cpp b/HDOJ/5919_dgutfly.cpp
new file mode 100644
index 0000000..ccb3d32
--- /dev/null
+++ b/HDOJ/5919_dgutfly.cpp
@@ -0,0 +1,149 @@
+/* ***********************************************
+┆  ┏┓　　　┏┓ ┆
+┆┏┛┻━━━┛┻┓ ┆
+┆┃　　　　　　　┃ ┆
+┆┃　　　━　　　┃ ┆
+┆┃　┳┛　┗┳　┃ ┆
+┆┃　　　　　　　┃ ┆
+┆┃　　　┻　　　┃ ┆
+┆┗━┓　马　┏━┛ ┆
+┆　　┃　勒　┃　　┆　　　　　　
+┆　　┃　戈　┗━━━┓ ┆
+┆　　┃　壁　　　　　┣┓┆
+┆　　┃　的草泥马　　┏┛┆
+┆　　┗┓┓┏━┳┓┏┛ ┆
+┆　　　┃┫┫　┃┫┫ ┆
+┆　　　┗┻┛　┗┻┛ ┆
+************************************************ */
+//#pragma comment(linker, "/STACK:102400000,102400000")
+#include <stdio.h>
+#include <string.h>
+#include <iostream>
+#include <algorithm>
+#include <vector>
+#include <queue>
+#include <stack>
+#include <set>
+#include <map>
+#include <string>
+#include <math.h>
+#include <stdlib.h>
+#include <bitset>
+using namespace std;
+
+#define rep(i,a,b) for (int i=(a),_ed=(b);i<=_ed;i++)
+#define per(i,a,b) for (int i=(b),_ed=(a);i>=_ed;i--)
+#define pb push_back
+#define mp make_pair
+const int inf_int = 2e9;
+const long long inf_ll = 2e18;
+#define inf_add 0x3f3f3f3f
+#define mod 1000000007
+#define LL long long
+#define ULL unsigned long long
+#define MS0(X) memset((X), 0, sizeof((X)))
+#define SelfType int
+SelfType Gcd(SelfType p,SelfType q){return q==0?p:Gcd(q,p%q);}
+SelfType Pow(SelfType p,SelfType q){SelfType ans=1;while(q){if(q&1)ans=ans*p;p=p*p;q>>=1;}return ans;}
+#define Sd(X) int (X); scanf("%d", &X)
+#define Sdd(X, Y) int X, Y; scanf("%d%d", &X, &Y)
+#define Sddd(X, Y, Z) int X, Y, Z; scanf("%d%d%d", &X, &Y, &Z)
+#define reunique(v) v.resize(std::unique(v.begin(), v.end()) - v.begin())
+#define all(a) a.begin(), a.end()
+#define   mem(x,v)      memset(x,v,sizeof(x))
+typedef pair<int, int> pii;
+typedef pair<long long, long long> pll;
+typedef vector<int> vi;
+typedef vector<long long> vll;
+inline int read(){int ra,fh;char rx;rx=getchar(),ra=0,fh=1;while((rx<'0'||rx>'9')&&rx!='-')rx=getchar();if(rx=='-')fh=-1,rx=getchar();while(rx>='0'&&rx<='9')ra*=10,ra+=rx-48,rx=getchar();return ra*fh;}
+
+const int N = 2e5 + 5;
+
+struct node
+{
+    int l,r,sum;
+}tree[N*40];
+
+int tot,cnt;
+
+void update(int l,int r,int &x,int y,int k,int val)
+{
+    int tmp = x;
+    x = ++tot;
+    tree[x] = tmp ? tree[tmp] : tree[y];
+    tree[x].sum += val;
+    if(l==r) return;
+    int mid = (l+r) >> 1;
+    if(k<=mid) update(l,mid,tree[x].l,tree[y].l,k,val);
+    else update(mid+1,r,tree[x].r,tree[y].r,k,val);
+}
+
+int query(int l,int r,int x,int k)
+{
+    if(l==r) return l;
+    int mid = (l+r) >> 1;
+    int sum = tree[tree[x].l].sum;
+    if(k<=sum) return query(l,mid,tree[x].l,k);
+    else return query(mid+1,r,tree[x].r,k-sum);
+}
+
+int getsum(int l,int r,int x,int L,int R)
+{
+    if(L<=l && r<=R) return tree[x].sum;
+    int mid = (l+r) >> 1;
+    int res = 0;
+    if(L<=mid) res += getsum(l,mid,tree[x].l,L,R);
+    if(R>mid) res += getsum(mid+1,r,tree[x].r,L,R);
+    return res;
+}
+
+int a[N],pos[N],rt[N];
+int ans[N];
+
+void init()
+{
+    tot = 0;
+    MS0(pos);
+    MS0(rt);
+}
+
+
+int main()
+{
+    //freopen("in.txt","r",stdin);
+    //freopen("out.txt","w",stdout);
+    //ios::sync_with_stdio(0);
+    //cin.tie(0);
+    int cas = 1;
+    int t = read();
+    while(t--)
+    {
+        int n = read(), m = read();
+        init();
+        for(int i=1;i<=n;i++) a[i] = read();
+        for(int i=n;i;i--)//倒着插入，以便从l开始计数
+        {
+            if(pos[a[i]])
+            {
+                update(1,n,rt[i],rt[i+1],pos[a[i]],-1);//去除重复的数
+            }
+            update(1,n,rt[i],rt[i+1],i,1);//前缀树继承上一次连接的
+            pos[a[i]] = i;
+        }
+        for(int i=1;i<=m;i++)
+        {
+            int l = read(), r = read();
+            l = (l + ans[i-1]) % n + 1;
+            r = (r + ans[i-1]) % n + 1;
+            if(l>r) swap(l,r);
+            int sum = (getsum(1,n,rt[l],l,r) + 1) / 2;//向上取整，题目要求
+            ans[i] = query(1,n,rt[l],sum);
+        }
+        printf("Case #%d:",cas++);
+        for(int i=1;i<=m;i++) printf(" %d",ans[i]);
+        printf("\n");
+    }
+
+
+    return 0;
+}