P3372 【模板】线段树 1 样例都没过，求助，大大滴感谢。

#include<bits/stdc++.h>
#define int long long
using namespace std;
const int N=4e5+10;
int lazy[N],s[N],a[N];
int n,m;
void build(int p,int l,int r)
{
    if(l==r)
    {
        s[p]=a[l];
        return;
    }
    int mid=(l+r)/2;
    build(p*2,l,mid);
    build(p*2+1,mid+1,r);
    s[p]=s[p*2]+s[p*2+1];
}
int f(int p,int l,int r,int ql,int qr,int k)
{
    if(ql<=l&&qr>=r)
    {
        s[p]+=(r-l+1)*k;
        lazy[p]+=k;
    }
    int mid=(l+r)/2;
    if(lazy[p])
    {
        s[p*2]+=lazy[p]*(mid-l+1);lazy[p*2]+=lazy[p];
        lazy[p*2+1]+=lazy[p];
        s[p*2+1]+=lazy[p]*(r-mid);lazy[p]=0;
    }
    if(ql<=mid) f(p*2,l,mid,ql,qr,k);
    if(qr>mid) f(p*2+1,mid+1,r,ql,qr,k);
}
int sum(int p,int l,int r,int ql,int qr)
{
    if(ql<=l&&qr>=r)
    {
        return s[p];
    }
    int mid=(l+r)/2;
    if(lazy[p])
    {
        s[p*2]+=lazy[p]*(mid-l+1);lazy[p*2]+=lazy[p];
        lazy[p*2+1]+=lazy[p];
        s[p*2+1]+=lazy[p]*(r-mid);lazy[p]=0;
    }
    int ans=0;
    if(ql<=mid) ans+=sum(p*2,l,mid,ql,qr);
    if(qr>mid) ans+=sum(p*2+1,mid+1,r,ql,qr);
    return ans; 
}
signed main()
{
    cin>>n>>m;
    for(int i=1;i<=n;i++) cin>>a[i];
    build(1,1,n);
    while(m--)
    {
        int op;
        cin>>op;
        if(op==1)
        {
            int x,y,k;
            cin>>x>>y>>k;
            f(1,1,n,x,y,k);
        }
        else
        {
            int x,y;
            cin>>x>>y;
            cout<<sum(1,1,n,x,y)<<endl;
        }
    }
    return 0;
 }