BZOJ 1828

program bzoj1828;

const maxn=100001;

    check=10000000;

    

type node=record

    l,r,s,a:longint;

end;



var t:array [0..maxn*5] of node;

    a,b,c:array [0..maxn] of longint;

    n,m,i,ans,mini:longint;

    

procedure swap(var x,y:longint);

begin

  x:=x xor y;

  y:=x xor y;

  x:=x xor y;

end;



procedure qsort(l,r:longint);

var i,j,mia,mib:longint;

begin

  i:=l; j:=r;

  mia:=a[(l+r) shr 1]; mib:=b[(l+r) shr 1];

  while i<=j do

    begin

      while (b[i]<mib) or (b[i]=mib) and (a[i]<mia) do inc(i); 

      while (b[j]>mib) or (b[j]=mib) and (a[j]>mia) do dec(j); 

        if i<=j then

          begin

            swap(a[i],a[j]); 

            swap(b[i],b[j]); 

            inc(i); 

            dec(j); 

          end; 

    end; 

    if i<r then qsort(i,r); 

    if j>l then qsort(l,j); 

end; 



function min(x,y:longint):longint;

begin

  if x<y then exit(x)

  else exit(y);

end;



procedure build(l,r,i:longint);

var mid:longint;

begin

  t[i].l:=l;

  t[i].r:=r;

  if l=r then 

    begin

      t[i].s:=c[l];

      exit;

    end;

    mid:=(l+r)>>1; 

    build(l,mid,i<<1); 

    build(mid+1,r,i<<1+1); 

    t[i].s:=min(t[i<<1].s,t[i<<1+1].s); 

end;



procedure pass(i,add:longint); 

var lch,rch:longint; 

begin

  lch:=i shl 1; 

  rch:=lch+1; 

  inc(t[lch].s,add); 

  inc(t[rch].s,add); 

  inc(t[lch].a,add); 

  inc(t[rch].a,add); 

  t[i].a:=0; 

end; 

   

procedure change(l,r,add,i:longint); 

var mid:longint; 

begin

  if (t[i].l=l)and(t[i].r=r) then

  begin

    inc(t[i].s,add); 

    inc(t[i].a,add); 

    exit; 

  end; 

  if t[i].a<>0 then pass(i,t[i].a); 

    mid:=(t[i].l+t[i].r)>>1; 

  if r<=mid then change(l,r,add,i<<1) 

    else 

  if l>mid then change(l,r,add,i<<1+1) 

    else 

    begin

        change(l,mid,add,i<<1); 

        change(mid+1,r,add,i<<1+1); 

    end; 

    t[i].s:=min(t[i<<1].s,t[i<<1+1].s); 

end; 

   

function getans(l,r,i:longint):longint; 

var mid,ans1,ans2:longint; 

begin

  if t[i].a<>0 then pass(i,t[i].a); 

  if (t[i].l=l)and(t[i].r=r) then exit(t[i].s); 

  ans1:=check; 

  ans2:=check; 

  mid:=(t[i].l+t[i].r)>>1; 

  if r<=mid then ans1:=getans(l,r,i<<1) 

  else 

  if l>mid then ans2:=getans(l,r,i<<1+1) 

  else 

    begin

      ans1:=getans(l,mid,i<<1); 

      ans2:=getans(mid+1,r,i<<1+1); 

    end; 

  exit(min(ans1,ans2)); 

end; 

     

begin

  read(n,m); 

  for i:=1 to n do read(c[i]); 

  build(1,n,1); 

  for i:=1 to m do read(a[i],b[i]); 

  sort(1,m); 

  for i:=1 to m do

    begin

      mini:=getans(a[i],b[i],1); 

      if mini>0 then

        begin

          inc(ans); 

          change(a[i],b[i],-1,1); 

        end; 

    end; 

  writeln(ans); 

end.