线段树(成段更新) POJ 3468 A Simple Problem with Integers

题目传送门

 /*
     线段树-成段更新：裸题，成段增减，区间求和
     注意：开long long:)
 */
 #include <cstdio>
 #include <iostream>
 #include <algorithm>
 #include <cstring>
 #include <cmath>
 using namespace std;

 #define lson l, mid, rt << 1
 #define rson mid + 1, r, rt << 1 | 1
 #define LL long long

 const int MAXN = 1e5 + ;
 const int INF = 0x3f3f3f3f;
 struct Node
 {
     LL sum, add;
 }node[MAXN << ];

 void push_up(int rt)
 {
     node[rt].sum = node[rt<<].sum + node[rt<<|].sum;
 }

 void push_down(int rt, int c)
 {
     if (node[rt].add)
     {
         node[rt<<].add += node[rt].add;
         node[rt<<|].add += node[rt].add;
         node[rt<<].sum += node[rt].add * (c - (c >> ));
         node[rt<<|].sum += node[rt].add * (c >> );
         node[rt].add = ;
     }
 }

 void build(int l, int r, int rt)
 {
     node[rt].add = ;
     if (l == r)    {scanf ("%I64d", &node[rt].sum);    return ;}
     int mid = (l + r) >> ;
     build (lson);    build (rson);

     push_up (rt);
 }

 void updata(int ql, int qr, int c, int l, int r, int rt)
 {
     if (ql <= l && r <= qr)    {node[rt].sum += (LL) c * (r - l + );    node[rt].add += c;    return ;}

     push_down (rt, r - l + );

     int mid = (l + r) >> ;
     if (ql <= mid)    updata (ql, qr, c, lson);
     if (qr > mid)    updata (ql, qr, c, rson);

     push_up (rt);
 }

 LL query(int ql, int qr, int l, int r, int rt)
 {
     if (ql <= l && r <= qr)    return node[rt].sum;

     push_down (rt, r - l + );

     int mid = (l + r) >> ;        LL ans = ;
     if (ql <= mid)    ans += query (ql, qr, lson);
     if (qr > mid)    ans += query (ql, qr, rson);

     return ans;
 }

 int main(void)        //POJ 3468 A Simple Problem with Integers
 {
     //freopen ("POJ_3468.in", "r", stdin);

     int n, q;
     while (scanf ("%d%d", &n, &q) == )
     {
         build (, n, );
         while (q--)
         {
             char s[];    int ql, qr, c;
             scanf ("%s", &s);
             if (s[] == 'Q')
             {
                 scanf ("%d%d", &ql, &qr);
                 printf ("%I64d\n", query (ql, qr, , n, ));
             }
             else
             {
                 scanf ("%d%d%d", &ql, &qr, &c);
                 updata (ql, qr, c, , n, );
             }
         }
     }

     return ;
 }