2.A Simple Problem with Integers

2.A Simple Problem with Integers

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.

输入

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.

输出

You need to answer all Q commands in order. One answer in a line.

样例输入

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

样例输出

4
55
9
15

ac代码

#include<cstdio>
#include<cstring>
#define maxl 1000000

long long n,q;
long long a[maxl];
struct node {long long l,r,sum,tag;};
node tree[maxl<<2];
node zerot={0,0,0,0};

void build(long long k,long long l,long long r)
{
    tree[k].l=l;tree[k].r=r;
    if(l==r)
    {   
        tree[k].sum=a[l];
        return;
    }
    long long mid=(tree[k].l+tree[k].r)>>1;
    build(k<<1,l,mid);
    build(k<<1|1,mid+1,r);
    tree[k].sum=tree[k<<1].sum+tree[k<<1|1].sum;
}

void prework()
{
    
    for(long long i=1;i<=n;i++)
        scanf("%lld",&a[i]);
    
    build(1,1,n);
}

void change(long long k)
{
    if(tree[k].l==tree[k].r)
        tree[k].sum+=tree[k].tag;
    else
    {
        tree[k].sum+=(tree[k].r-tree[k].l+1)*tree[k].tag;
        tree[k<<1].tag+=tree[k].tag;
        tree[k<<1|1].tag+=tree[k].tag;
    }
    tree[k].tag=0;
}

void add(long long k,long long l,long long r,long long x)
{
    if(tree[k].tag)
        change(k);
    if(tree[k].l==l && tree[k].r==r)
    {
        tree[k].tag+=x;
        return;
    }
    tree[k].sum+=(r-l+1)*x;
    long long mid=(tree[k].l+tree[k].r)>>1;
    if(r<=mid)
        add(k<<1,l,r,x);
    else
        if(l>mid)
            add(k<<1|1,l,r,x);
        else
            add(k<<1,l,mid,x),add(k<<1|1,mid+1,r,x);
}

long long query(long long k,long long l,long long r)
{
    if(tree[k].tag)
        change(k);
    long long sum,mid=(tree[k].l+tree[k].r)>>1;
    if(tree[k].l==l && tree[k].r==r)
        return tree[k].sum;
    if(r<=mid)
        return query(k<<1,l,r);
    else
        if(l>mid)
            return query(k<<1|1,l,r);
        else
            return query(k<<1,l,mid)+query(k<<1|1,mid+1,r);
}

void mainwork()
{
    long long l,r,x;
    char c[2];
    //printf("%lld\n",q);
    for(long long i=1;i<=q;i++)
    {
        //getchar();
        scanf("%s",c);
        //getchar();
        //printf("%c",c);
        if(c[0]=='C')
        {
            //printf("1\n");
            scanf("%lld%lld%lld",&l,&r,&x);
            add(1,l,r,x);
        }
        if(c[0]=='Q')
        {
            scanf("%lld%lld",&l,&r);
            printf("%lld\n",query(1,l,r));
        }
    }
}

int main()
{
    while(scanf("%lld%lld",&n,&q)!=EOF){
        memset(tree,0,sizeof(tree));
        prework();
        mainwork();
    }
    
    return 0;
}