二次联通门 : cogs 920. [東方S1] 琪露诺

/*
cogs 920. [東方S1] 琪露诺 dp 方程为dp[i] = max (dp[i - L], dp[i - L + 1] .... dp[i - R - 1], dp[i - R]); 要用单调队列优化 记录路径是只需像最短路问题一样记录前驱
后递归打印即可
*/
#include <cstring>
#include <cstdio> void read (int &now)
{
register char word = getchar ();
bool temp = false;
for (now = ; word < '' || word > ''; word = getchar ())
if (word == '-')
temp = true;
for (; word >= '' && word <= ''; now = now * + word - '', word = getchar ());
if (temp)
now = -now;
} //#define Online
#define INF 1e9 int N, L, R, Answer = -INF; int pos;
#define Max 1000001
int dp[Max]; int Queue[Max];
int Head, Tail; int value[Max], pre[Max]; void Print_road (int now)
{
if (pre[now] != -)
Print_road (pre[now]);
printf ("%d ", now);
} int main (int argc, char *argv[])
{ #ifdef Online freopen ("iceroad.in", "r", stdin);
freopen ("iceroad.out", "w", stdout); #endif read (N);
read (L);
read (R); for (int i = ; i <= N; i ++)
read (value[i]);
Tail = ; memset (pre, -, sizeof pre);
for (register int i = L, res; i <= N; i ++)
{
if (i - L <= )
continue;
res = dp[i - L];
for (; Head <= Tail && (Queue[Head] + L > i || (Queue[Head] + R < i) || (Queue[Head] > i)); Head ++);
for (; Head <= Tail && (res > dp[Queue[Tail]]); Tail --);
Queue[++ Tail] = i - L;
pre[i] = Queue[Head];
dp[i] = value[i] + dp[Queue[Head]];
if (Answer < dp[i])
{
Answer = dp[i];
pos = i;
}
} printf ("%d\n", Answer);
Print_road (pos);
printf ("-1"); return ;
}
05-23 02:31