HDU 5074 DP 2014 Anshan on-site competition questions

HDU 5074 http://acm.hdu.edu.cn/showproblem.php? PID = 1, 5074

Very water DP, pay attention to a [I-1] And a [I] Positive and negative differentiation of the state transfer, and then O (N ^ 3) can be easily solved, my DP is quite weak, and it seems that it is also the level of cf c.

//#pragma comment(linker, "/STACK:102400000,102400000")#include <cstdio>#include <cstring>#include <algorithm>#include <string>#include <iostream>#include <iomanip>#include <cmath>#include <map>#include <set>#include <queue>using namespace std;#define ls(rt) rt*2#define rs(rt) rt*2+1#define ll long long#define ull unsigned long long#define rep(i,s,e) for(int i=s;i<e;i++)#define repe(i,s,e) for(int i=s;i<=e;i++)#define CL(a,b) memset(a,b,sizeof(a))#define IN(s) freopen(s,"r",stdin)#define OUT(s) freopen(s,"w",stdout)const ll ll_INF = ((ull)(-1))>>1;const double EPS = 1e-8;const double pi = acos(-1.0);const ll INF = 1e18;const int MAXN = 100+10;int mat[MAXN][MAXN];ll dp[MAXN][MAXN];int a[MAXN];int n,m;ll solve(){    for(int i=2;i<=n;i++)    {        if(a[i]>0)        {            if(a[i-1]>0)                dp[i][a[i]]=max(dp[i][a[i]],dp[i-1][a[i-1]]+mat[a[i-1]][a[i]]);            else                for(int k=1;k<=m;k++)                    dp[i][a[i]]=max(dp[i][a[i]],dp[i-1][k]+mat[k][a[i]]);        }        else        {            if(a[i-1]>0)            {                for(int j=1;j<=m;j++)                    dp[i][j]=max(dp[i][j],dp[i-1][a[i-1]] + mat[a[i-1]][j]);            }            else            {                for(int j=1;j<=m;j++)                {                    for(int k=1;k<=m;k++)                       dp[i][j]=max(dp[i][j],dp[i-1][k]+mat[k][j]);                }            }        }    }    ll ans=0LL;    for(int i=1;i<=m;i++)        ans=max(ans,dp[n][i]);    return ans;}int main(){    //IN("hdu5074.txt");   int ncase;    scanf("%d",&ncase);    while(ncase--)    {        scanf("%d%d",&n,&m);        CL(mat,0);        for(int i=1;i<=m;i++)            for(int j=1;j<=m;j++)                scanf("%d",&mat[i][j]);        a[0]=0;        for(int i=1;i<=n;i++)            scanf("%d",&a[i]);        CL(dp,0);        printf("%I64d\n",solve());    }    return 0;}

HDU 5074 DP 2014 Anshan on-site competition questions