……
by BPG_ning @ 2022-09-10 09:40:01
```
#include<cstdio>
#include<string>
#include<cstring>
using namespace std;
int max(int a,int b) {
return a>b?a:b;
}
int min(int a,int b) {
return a<b?a:b;
}
inline int read() {
int ret=0,f=1;
char c=getchar();
for(; c<'0'||c>'9'; c=getchar()) if(c=='-') f=-f;
for(; c>='0'&&c<='9'; c=getchar()) ret=ret*10+c-'0';
return ret*f;
}
const int maxn=60;
int n,c;
int p[maxn],e[maxn],sum[maxn];
int f[maxn][maxn][5];
signed main(void) {
n=read();
c=read();
memset(f,127,sizeof(f));
for(int i=1; i<=n; i++) {
p[i]=read();
e[i]=read();
sum[i]=sum[i-1]+e[i];
}
f[c][c][0]=f[c][c][1]=0;
for(int l=2; l<=n; l++) {
for(int i=1; i+l-1<=n; i++) {
int j=i+l-1;
f[i][j][0]=min(f[i+1][j][0]+(p[i+1]-p[i])*(sum[n]+sum[i]-sum[j]),f[i+1][j][1]+(p[j]-p[i])*(sum[n]+sum[i]-sum[j]));
f[i][j][1]=min(f[i][j-1][0]+(p[j]-p[i])*(sum[i-1]+sum[n]-sum[j-1]),f[i][j-1][1]+(p[j]-p[j-1])*(sum[i-1]+sum[n]-sum[j-1]));
}
}
int ans=min(f[1][n][0],f[1][n][1]);
printf("%d\n",ans);
return 0;
}
by BPG_ning @ 2022-09-10 09:41:31
@[BPG_ning](/user/551803) 啊喂！下次要at我啊，不然我怎么知道有回复了
by 柠檬布丁吖 @ 2022-09-10 15:02:11