实现功能——1：区间覆盖值；2：区间求和
相比直接的区间加，这个要注重顺序，因为操作有顺序之分。所以这里面的tag应该有个pushup操作（本程序中的ext）
1 var 2 i,j,k,l,m,n,a1,a2,a3,a4:longint; 3 a,b,d:array[0..100000] of longint; 4 function max(x,y:longint):longint;inline; 5 begin 6 if x>y then max:=x else max:=y; 7 end; 8 function min(x,y:longint):longint;inline; 9 begin10 if xy then17 begin18 b[z*2]:=b[z];d[z*2]:=1;19 b[z*2+1]:=b[z];d[z*2+1]:=1;20 end;21 b[z]:=0;d[z]:=0;22 end;23 function op(z,x,y,l,r,p:longint):longint;inline;24 var a3,a4:longint;25 begin26 if l>r then exit(0);27 if (x=l) and (y=r) then28 begin29 if d[z]=1 then a[z]:=b[z]*(r-l+1);30 d[z]:=1;b[z]:=p;31 exit(p*(r-l+1)-a[z]);32 end;33 ext(z,x,y);34 a3:=op(z*2,x,(x+y) div 2,l,min(r,(x+y) div 2),p);35 a4:=op(z*2+1,(x+y) div 2+1,y,max((x+y) div 2+1,l),r,p);36 a[z]:=a[z]+a3+a4;37 exit(a3+a4);38 end;39 function cal(z,x,y,l,r:longint):longint;inline;40 begin41 if l>r then exit(0);42 if d[z]=1 then exit(b[z]*(r-l+1));43 if (x=l) and (y=r) then exit(a[z]);44 exit(cal(z*2,x,(x+y) div 2,l,min(r,(x+y) div 2))+cal(z*2+1,(x+y) div 2+1,y,max(l,(x+y) div 2+1),r));45 end;46 procedure built(z,x,y:longint);inline;47 begin48 if x=y then49 read(a[z])50 else51 begin52 built(z*2,x,(x+y) div 2);53 built(z*2+1,(x+y) div 2+1,y);54 a[z]:=a[z*2]+a[z*2+1];55 end;56 b[z]:=0;d[z]:=0;57 end;58 begin59 readln(n,m);60 built(1,1,n);61 readln;62 for i:=1 to m do63 begin64 read(j);65 case j of66 1:begin67 readln(a1,a2,a3);68 op(1,1,n,a1,a2,a3);69 end;70 2:begin71 readln(a1,a2);72 writeln(cal(1,1,n,a1,a2));73 end;74 else halt;75 end;76 end;77 end.78