#include<iostream>
#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<string>
#define ll long long
using namespace std;
int T,n,m;
ll a[1000001];
class Segtree
{
public:ll sum[1000001*5],mx[1000001*5],smx[1000001*5],cnt[1000001*5],fl[1000001*5];void pushup(int pos){sum[pos]=sum[pos<<1]+sum[pos<<1|1];if(mx[pos<<1]>mx[pos<<1|1]){mx[pos]=mx[pos<<1];cnt[pos]=cnt[pos<<1];if(mx[pos<<1|1]>smx[pos<<1])smx[pos]=mx[pos<<1|1];else smx[pos]=smx[pos<<1];}if(mx[pos<<1]<mx[pos<<1|1]){mx[pos]=mx[pos<<1|1];cnt[pos]=cnt[pos<<1|1];if(mx[pos<<1]>smx[pos<<1|1])smx[pos]=mx[pos<<1];else smx[pos]=smx[pos<<1|1];}if(mx[pos<<1]==mx[pos<<1|1]){mx[pos]=mx[pos<<1];cnt[pos]=cnt[pos<<1]+cnt[pos<<1|1];if(smx[pos<<1]>smx[pos<<1|1])smx[pos]=smx[pos<<1];else smx[pos]=smx[pos<<1|1];}}void pushdown(int pos){if(fl[pos]>=0){if(mx[pos<<1]>fl[pos]){sum[pos<<1]-=(mx[pos<<1]-fl[pos])*cnt[pos<<1];fl[pos<<1]=mx[pos<<1]=fl[pos];}if(mx[pos<<1|1]>fl[pos]){sum[pos<<1|1]-=(mx[pos<<1|1]-fl[pos])*cnt[pos<<1|1];fl[pos<<1|1]=mx[pos<<1|1]=fl[pos];}fl[pos]=-1;}}void build(int l,int r,int pos){if(l==r){sum[pos]=mx[pos]=a[l];cnt[pos]=1;fl[pos]=smx[pos]=-1;return;}int mid=l+r>>1;build(l,mid,pos<<1);build(mid+1,r,pos<<1|1);pushup(pos);fl[pos]=-1;}void change(int l,int r,int al,int ar,ll v,int pos){int mid=l+r>>1;if(l==al && r==ar){if(v>=mx[pos])return;if(smx[pos]<v && v<mx[pos]){sum[pos]-=(mx[pos]-v)*cnt[pos];fl[pos]=mx[pos]=v;return;}change(l,mid,al,mid,v,pos<<1);change(mid+1,r,mid+1,ar,v,pos<<1|1);pushup(pos);return;}pushdown(pos);if(ar<=mid)change(l,mid,al,ar,v,pos<<1);if(al>mid)change(mid+1,r,al,ar,v,pos<<1|1);if(al<=mid && ar>mid){change(l,mid,al,mid,v,pos<<1);change(mid+1,r,mid+1,ar,v,pos<<1|1);}pushup(pos);}ll askmax(int l,int r,int al,int ar,int pos){if(l==al && r==ar)return mx[pos];int mid=l+r>>1;pushdown(pos);if(ar<=mid)return askmax(l,mid,al,ar,pos<<1);if(al>mid)return askmax(mid+1,r,al,ar,pos<<1|1);if(al<=mid && ar>mid){ll t1=askmax(l,mid,al,mid,pos<<1),t2=askmax(mid+1,r,mid+1,ar,pos<<1|1);return t1>t2?t1:t2;}}ll asksum(int l,int r,int al,int ar,int pos){if(l==al && r==ar)return sum[pos];int mid=l+r>>1;pushdown(pos);if(ar<=mid)return asksum(l,mid,al,ar,pos<<1);if(al>mid)return asksum(mid+1,r,al,ar,pos<<1|1);if(al<=mid && ar>mid)return asksum(l,mid,al,mid,pos<<1)+asksum(mid+1,r,mid+1,ar,pos<<1|1);}
}segtree;
int main()
{scanf("%d",&T);while(T--){scanf("%d%d",&n,&m);for(int i=1;i<=n;i++)scanf("%lld",&a[i]);segtree.build(1,n,1);int mod,x,y;ll t;while(m--){scanf("%d",&mod);if(mod==0){scanf("%d%d%lld",&x,&y,&t);segtree.change(1,n,x,y,t,1);}if(mod==1){scanf("%d%d",&x,&y);printf("%lld\n",segtree.askmax(1,n,x,y,1));}if(mod==2){scanf("%d%d",&x,&y);printf("%lld\n",segtree.asksum(1,n,x,y,1));}}}return 0;
}