poj 3468 A Simple Problem with Integers(区间查询区间更新)

题目：

You have N integers, A1, A2, … , AN. You need to deal with two kinds of operations. One type of operation is to add some given number to each number in a given interval. The other is to ask for the sum of numbers in a given interval.

Input
The first line contains two numbers N and Q. 1 ≤ N,Q ≤ 100000.
The second line contains N numbers, the initial values of A1, A2, … , AN. -1000000000 ≤ Ai ≤ 1000000000.
Each of the next Q lines represents an operation.
“C a b c” means adding c to each of Aa, Aa+1, … , Ab. -10000 ≤ c ≤ 10000.
“Q a b” means querying the sum of Aa, Aa+1, … , Ab.

Output
You need to answer all Q commands in order. One answer in a line.
Sample Input
10 5
1 2 3 4 5 6 7 8 9 10
Q 4 4
Q 1 10
Q 2 4
C 3 6 3
Q 2 4
Sample Output
4
55
9
15
Hint
The sums may exceed the range of 32-bit integers.

题意：

给你一个序列，要你进行区间修改以及区间查询.

ps:

模板题，lazy标记的使用，没啥说的，注意lazy是累加，还有sum更新的方法是加上区间长乘以更新值，还有一个地方坑了我好久找bug，写在代码注释里了。

代码：

#include <iostream>#include <cstdio>#include <cstring>#include <algorithm>#define ls (rt<<1)#define rs (rt<<1|1)#define lson L,mid,ls#define rson mid+1,R,rs#define def_mid int mid=(L+R)>>1#define ll long long#define INF 0x3f3f3f3fusing namespace std;const int maxn = 123456;ll sum[maxn<<2],lazy[maxn<<2];ll a[maxn];void pushup(int rt){    sum[rt]=sum[ls]+sum[rs];}void pushlazy(int lz,int len,int rt){    sum[rt]+=(ll)lz*len;//被这里坑了两个int类型相乘会爆int所以在这里要强转为ll    lazy[rt]+=lz;}void pushdown(int L,int R,int rt){    if(lazy[rt]!=0)    {        def_mid;        pushlazy(lazy[rt],mid-L+1,ls);        pushlazy(lazy[rt],R-mid,rs);        lazy[rt]=0;    }    return;}void build(int L,int R,int rt){    lazy[rt]=0;    if(L==R)    {        sum[rt]=a[L];        return;    }    def_mid;    build(lson);    build(rson);    pushup(rt);}void update(int l,int r,int L,int R,int rt,int k){    if(l<=L&&r>=R)    {        sum[rt]+=k*(R-L+1);        lazy[rt]+=k;        return;    }    pushdown(L,R,rt);    def_mid;    if(l<=mid)        update(l,r,lson,k);    if(r>mid)        update(l,r,rson,k);    pushup(rt);}ll querysum(int l,int r,int L,int R,int rt){    if(l<=L&&r>=R)        return sum[rt];    pushdown(L,R,rt);    def_mid;    ll ret=0;    if(l<=mid)        ret+=querysum(l,r,lson);    if(r>mid)        ret+=querysum(l,r,rson);    return ret;}int main(){    int n,q,k;    while(scanf("%d%d",&n,&q)!=EOF)    {        memset(lazy,0,sizeof(lazy));        memset(sum,0,sizeof(sum));        memset(a,0,sizeof(a));        char op[3];        int l,r;        for(int i=1;i<=n;i++)            scanf("%lld",&a[i]);        build(1,n,1);        while(q--)        {            scanf("%s%d%d",op,&l,&r);            if(op[0]=='Q')                printf("%lld\n",querysum(l,r,1,n,1));            else            {                scanf("%d",&k);                update(l,r,1,n,1,k);            }        }    }    return 0;}