@[kirihara233](/user/701221) 没有加入新的点
by Hayzeros @ 2022-11-24 14:16:41
@[kirihara233](/user/701221) 少了句```q[++r]=i```
by yinhee @ 2022-11-24 14:28:07
@[kirihara233](/user/701221) 帮您调过了。
几点问题（很多地方我是为了方便调试改的，改回去也应该没什么问题）：
- 计算斜率时最好强制类型转换成 `long double` 防止精度损失~~消失~~，或进行一个移项。
- 不要忘记加点。
- 刚开始要默认加入一个点 $0$，否则第一个任务总是会被分出去的。
- 弹出尾部时的条件有问题。
- 最好写 `l<r` 而不是 `l<=r`，当 `l==r` 时可能会有问题出现
[~~综上所述，我要给我的学习笔记引个流！~~](https://www.cnblogs.com/Keven-He/p/16027921.html)
```cpp
/*
本提交仅用于帮助@[kirihara233](/user/701221)调试代码
*/
#include<stdio.h>
#define N 5009
#define int long long
inline int read()
{
register int ret = 0, f = 1;
register char ch = getchar();
while (ch < '0' || ch > '9')
(ch == '-') ? f = -1 : 0, ch = getchar();
while (ch >= '0' && ch <= '9')
ret = (ret << 1) + (ret << 3) + (ch ^ 48), ch = getchar();
return ret * f;
}
int dp[N], t[N], f[N], q[N];
inline int min(int a, int b) {return a < b ? a : b;}
#define slope(j, k) (long double)((long double)((long double)(dp[k]) - (long double)(dp[j])) / (long double)((long double)(f[k]) - (long double)(f[j])))
signed main()
{
register int n = read(), s = read(), i, j, l = 1, r = 1;
for (i = 1;i <= n;++ i)
t[i] = read() + t[i - 1], f[i] = read() + f[i - 1];
for (i = 1;i <= n;++ i)
{
while (l < r && slope(q[l], q[l + 1]) <= (long double)(t[i] + s))
++ l;
dp[i] = dp[q[l]] - (t[i] + s) * f[q[l]] + t[i] * f[i] + s * f[n];
while (l < r && slope(q[r - 1], q[r]) >= slope(q[r], i))
-- r;
q[++ r] = i;
// for (j = 0;j < i;++ j)
// dp[i] = min(dp[i], dp[j] + t[i] * (f[i] - f[j]) + s * (f[n] - f[j]));
}
printf("%lld", dp[n]);
return 0;
}
```
by K8He @ 2022-11-24 14:36:52
@[Hayzeros](/user/130819) @[yinhee](/user/578590) @[Keven_He](/user/306045) 谢谢！
by char_cha_ch @ 2022-11-24 18:37:27