附 [color=red]0分[/color]代码:
program rq314;
var
f:array [1..19,0..11,0..11] of longint;
num:array [1..19,0..11] of longint;
n,a,b,c,i,x,y,p,q,j:longint;
function max4(a,b,c,d:longint):longint;
begin
if a>b then max4:=a
else max4:=b;
if c>max4 then max4:=c;
if d>max4 then max4:=d;
end;
function max2(a,b:longint):longint;
begin
if a>b then exit(a)
else exit(b);
end;
begin
readln(n);
for i:=1 to n do
begin
readln(a,b,c);
p:=a+b-1;
if p>n then q:=b-(p-n)
else q:=b;
num[p,q]:=c;
end;
readln(a,b,c);
f[1,1,1]:=num[1,1];
p:=0; q:=0;
for i:=2 to 2*n-1 do
begin
for x:=1 to n-abs(i-n) do
for y:=1 to n-abs(i-n) do
begin
p:=max4(f[i-1,x-1,y-1],f[i-1,x-1,y],f[i-1,x,y-1],f[i-1,x,y]);
if x=y then f[i,x,y]:=p+num[i,x]
else f[i,x,y]:=p+num[i,x]+num[i,y];
end;
end;
writeln(f[2*n-1,1,1]);
readln;
end.