diff --git a/POJ/3468_acdreamers.cpp b/POJ/3468_acdreamers.cpp
new file mode 100644
index 0000000..ee9be84
--- /dev/null
+++ b/POJ/3468_acdreamers.cpp
@@ -0,0 +1,93 @@
+#include <stdio.h>
+#define N 111111
+
+#define LL long long
+#define lson l,m,rt<<1
+#define rson m+1,r,rt<<1|1
+
+LL add[N<<2];
+LL sum[N<<2];
+
+void PushUP(int rt)
+{
+    sum[rt]=sum[rt<<1]+sum[rt<<1|1];
+}
+
+void PushDown(int rt,int m)
+{
+    if(add[rt])
+    {
+        add[rt<<1]+=add[rt];
+        add[rt<<1|1]+=add[rt];
+        sum[rt<<1]+=(m-(m>>1))*add[rt];
+        sum[rt<<1|1]+=(m>>1)*add[rt];
+        add[rt]=0;
+    }
+}
+
+void Build(int l,int r,int rt)
+{
+    add[rt]=0;
+    if(l==r)
+    {
+        scanf("%I64d",&sum[rt]);
+        return;
+    }
+    int m=(l+r)>>1;
+    Build(lson);
+    Build(rson);
+    PushUP(rt);
+}
+
+void Update(int L,int R,int c,int l,int r,int rt)
+{
+    if(L<=l&&R>=r)
+    {
+        add[rt]+=c;
+        sum[rt]+=(LL)c*(r-l+1);
+        return;
+    }
+    PushDown(rt,r-l+1);
+    int m=(l+r)>>1;
+    if(L<=m)
+        Update(L,R,c,lson);
+    if(R>m)
+        Update(L,R,c,rson);
+    PushUP(rt);
+}
+
+LL Query(int L,int R,int l,int r,int rt)
+{
+    if(L<=l&&R>=r)
+        return sum[rt];
+    PushDown(rt,r-l+1);
+    int m=(l+r)>>1;
+    LL ret=0;
+    if(L<=m)   ret+=Query(L,R,lson);
+    if(R>m)    ret+=Query(L,R,rson);
+    return ret;
+}
+
+int main()
+{
+    int m,n;
+    scanf("%d%d",&n,&m);
+    Build(1,n,1);
+    while(m--)
+    {
+        char s[5];
+        int a,b,c;
+        scanf("%s",s);
+        if(s[0]=='Q')
+        {
+            scanf("%d%d",&a,&b);
+            printf("%I64d\n",Query(a,b,1,n,1));
+        }
+        else
+        {
+            scanf("%d%d%d",&a,&b,&c);
+            Update(a,b,c,1,n,1);
+        }
+    }
+    return 0;
+}