[TYVJ1061] Mobile Service|动态规划|滚动数组

#include<iostream>
#include<cstdio>
#include<cstring>
#include<cstdlib>
#include<algorithm>
#include<cmath>
#define inf 1000000000
using namespace std;
int l,n,x,r,ans,a[205][205],f[2][205][205],t[1005];
inline int read()
{
    int a=0,f=1; char c=getchar();
    while (c<‘0‘||c>‘9‘) {if (c==‘-‘) f=-1; c=getchar();}
    while (c>=‘0‘&&c<=‘9‘) {a=a*10+c-‘0‘; c=getchar();}
    return a*f;
}
int main()
{
    l=read(); n=read();
    for (int i=1;i<=l;i++)
        for (int j=1;j<=l;j++)
            a[i][j]=read();
    for (int i=1;i<=n;i++) t[i]=read();
    ans=inf;
    for (int i=1;i<=l;i++)
        for (int j=1;j<=l;j++)
            f[r][i][j]=inf;
    f[r][1][3]=a[2][t[1]];
    f[r][2][3]=a[1][t[1]];
    f[r][1][2]=a[3][t[1]];
    for (int k=1;k<n;k++)
    {
        r^=1;
        for (int i=1;i<=l;i++)
            for (int j=1;j<=l;j++)
                f[r][i][j]=inf;
        for (int i=1;i<=l;i++)
            for (int j=1;j<=l;j++)
            {
                f[r][j][t[k]]=min(f[r][j][t[k]],f[r^1][i][j]+a[i][t[k+1]]);
                f[r][i][t[k]]=min(f[r][i][t[k]],f[r^1][i][j]+a[j][t[k+1]]);
                f[r][i][j]=min(f[r][i][j],f[r^1][i][j]+a[t[k]][t[k+1]]);
            }
    }
    for (int i=1;i<=l;i++)
        for (int j=1;j<=l;j++)
            ans=min(ans,f[r][i][j]);
    printf("%d",ans);
    return 0;
}