diff --git a/HDOJ/1166_cszlg.cpp b/HDOJ/1166_cszlg.cpp
new file mode 100644
index 0000000..c74930c
--- /dev/null
+++ b/HDOJ/1166_cszlg.cpp
@@ -0,0 +1,90 @@
+/*简单说下这个题，题目意思很明显，线段树的单点更新，线段树，听大牛们说，线段树一般变化最大的就是询问，和更新，所以，大家只要把询问和更新给弄明白了，这题也就明白了，还有，线段树对递归要求有点高，递归不是很熟的同学，最好去把递归复习几遍，附上代码*/
+#include<stdio.h>
+#include<string.h>
+#define maxn 50000
+int ans;
+struct node 
+{
+    int left,right,sum;
+    int mid()
+    {
+        return (left+right)>>1;
+    }
+}tree[maxn*4];
+void btree(int left,int right,int rt)
+{
+    tree[rt].left=left;
+    tree[rt].right=right;
+    if(left==right)
+    {
+        scanf("%d",&tree[rt].sum);
+        return ;
+    }
+    int mid=tree[rt].mid();
+    btree(left,mid,rt<<1);
+    btree(mid+1,right,rt<<1|1);
+    tree[rt].sum=tree[rt<<1].sum+tree[rt<<1|1].sum;
+}
+void query(int left,int right,int rt,int L,int R)
+{
+    if(L<=left&&right<=R)
+    {
+        ans+=tree[rt].sum;
+        return;
+    }
+    int mid=tree[rt].mid();
+    if(R<=mid)
+        query(left,mid,rt<<1,L,R);
+    else if(L>mid)
+        query(mid+1,right,rt<<1|1,L,R);
+    else
+    {
+        query(left,mid,rt<<1,L,R);
+        query(mid+1,right,rt<<1|1,L,R);
+    }
+}
+void update(int left,int right,int rt,int pos,int add)
+{
+    if(left==right)
+    {
+        tree[rt].sum+=add;
+        return;
+    }
+    int mid=tree[rt].mid();
+    if(pos<=mid)
+        update(left,mid,rt<<1,pos,add);
+    else
+        update(mid+1,right,rt<<1|1,pos,add);
+    tree[rt].sum=tree[rt<<1].sum+tree[rt<<1|1].sum;
+}
+int main()
+{
+    int t,n,cnt;
+    int a,b;
+    char str[10];
+    cnt=1;
+    scanf("%d",&t);
+    while(t--)
+    {
+        scanf("%d",&n);
+        btree(1,n,1);
+        printf("Case %d:\n",cnt++);
+        while(scanf("%s",str))
+        {
+            if(str[0]=='E')
+                break;
+            scanf("%d%d",&a,&b);
+            if(str[0]=='Q')
+            {
+                ans=0;
+                query(1,n,1,a,b);
+                printf("%d\n",ans);
+            }
+            else if(str[0]=='A')
+                update(1,n,1,a,b);
+            else 
+                update(1,n,1,a,-b);
+        }
+    }
+    return 0;
+}