[TyvjP1313] [NOIP2010初赛]烽火传递（单调队列 + DP）

传送门

就是个单调队列+DP嘛。

——代码

#include <cstdio>

const int MAXN = 1000001;
int n, m, h = 1, t = 1, ans = ~(1 << 31);
int q[MAXN], a[MAXN], f[MAXN];

inline int min(int x, int y)
{
    return x < y ? x : y;
}

int main()
{
    int i;
    scanf("%d %d", &n, &m);
    for(i = 1; i <= n; i++) scanf("%d", &a[i]);
    for(i = 1; i <= n; i++)
    {
        while(h <= t && q[h] < i - m) h++;
        f[i] = f[q[h]] + a[i];
        while(h <= t && f[q[t]] > f[i]) t--;
        q[++t] = i;
     }
     for(i = n - m + 1; i <= n; i++) ans = min(ans, f[i]);
     printf("%d
", ans);
     return 0;
}