我是蒟蒻

样例还有前6个点都是可以过的，但是不知道为什么后面过不了了

#include<bits/stdc++.h>  
#define ll long long  
using namespace std;  

const int MAXN = 10000005;  
ll ans;
ll n, q, k;  
ll a[MAXN];  
ll tree[4 * MAXN];  
ll lz[4 * MAXN];
bool cover[4 * MAXN];

void pushdown(int p, int s, int t) {  
    if (cover[p]) {  
        int mid = (s + t) / 2;  
        tree[2 * p] = tree[p];  
        tree[2 * p + 1] = tree[p];  
        lz[2 * p] = 0;  
        lz[2 * p + 1] = 0;  
        cover[2 * p] = true;  
        cover[2 * p + 1] = true;  
        cover[p] = false;  
    }  
    if (lz[p] != 0) {  
        int mid = (s + t) / 2;  
        tree[2 * p] += lz[p];  
        tree[2 * p + 1] += lz[p];  
        lz[2 * p] += lz[p];  
        lz[2 * p + 1] += lz[p];  
        lz[p] = 0;  
    }  
}  

void build(int s, int t, int p) {  
    if (s == t) {  
        tree[p] = a[s];  
        return;  
    }  
    int mid = (s + t) / 2;  
    build(s, mid, 2 * p);  
    build(mid + 1, t, 2 * p + 1);  
    tree[p] = max(tree[2 * p], tree[2 * p + 1]);  
}  

void change(int l, int r, ll x, int s, int t, int p) {  
    if (l <= s && r >= t) {  
        tree[p] = x;  
        lz[p] = 0;  
        cover[p] = true;  
        return;  
    }  
    pushdown(p, s, t);  
    int mid = (s + t) / 2;  
    if (l <= mid) change(l, r, x, s, mid, 2 * p);  
    if (r > mid) change(l, r, x, mid + 1, t, 2 * p + 1);  
    tree[p] = max(tree[2 * p], tree[2 * p + 1]);  
}  

void update(int l, int r, ll k, int s, int t, int p) {  
    if (l <= s && r >= t) {  
        tree[p] += k;  
        lz[p] += k;  
        return;  
    }  
    pushdown(p, s, t);  
    int mid = (s + t) / 2;  
    if (l <= mid) update(l, r, k, s, mid, 2 * p);  
    if (r > mid) update(l, r, k, mid + 1, t, 2 * p + 1);  
    tree[p] = max(tree[2 * p], tree[2 * p + 1]);  
}  

ll query(int l, int r, int s, int t, int p) {  
    if (l <= s && r >= t) {  
        return tree[p];  
    }  
    pushdown(p, s, t);  
    int mid = (s + t) / 2;  
    if (l <= mid) ans = max(ans, query(l, r, s, mid, 2 * p));  
    if (r > mid) ans = max(ans, query(l, r, mid + 1, t, 2 * p + 1));  
    return ans;  
}  
int main(){
    ios::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);

//  freopen("P1253_6.in","r",stdin);
//  freopen("cesh.txt","w",stdout);
    cin>>n>>q;
    for(int i=1;i<=n;i++){
        cin>>a[i];
    }
    build(1,n,1);
    for(int i=1;i<=q;i++){
        int op=0;
        cin>>op;
        if(op==1){
            int l,r,x=0;
            cin>>l>>r>>x;
            change(l,r,x,1,n,1);
        }
        if(op==2){
            int l,r;
            cin>>l>>r>>k;
            update(l,r,k,1,n,1);
        }
        if(op==3){
            int l,r=0;
            cin>>l>>r;
            ans = LLONG_MIN;
            ans=query(l,r,1,n,1);
            cout<<ans<<endl;
        }
    }
    return 0;
}