hdu 5375 Gray code 【 dp 】

dp[i][j]表示第i位取j的时候取得的最大的分数

然后分s[i]是不是问号，s[i-1]是不是问号这大的四种情况讨论

 #include<cstdio>
 #include<cstring>
 #include<iostream>
 #include<algorithm>
 using namespace std;

 const int maxn = ;
 int dp[maxn][];
 int a[maxn];
 char s[maxn];
 int n;

 int main(){
     int T;
     scanf("%d",&T);
     int kase = ;
     while(T--){
         cin >> (s+);
         n = strlen(s+);
         for(int i = ;i <= n;i++) scanf("%d",&a[i]);

         s[] = '';
         memset(dp,,sizeof(dp));

         for(int i = ;i <= n;i++){
             if(s[i] == '?'){
                 if(s[i-] == '?'){
                     dp[i][] = max(dp[i-][] + a[i],dp[i-][]);
                     dp[i][] = max(dp[i-][] + a[i],dp[i-][]);
                 }
                 else{
                     if(s[i-] == '') dp[i][] = dp[i-][],dp[i][] = dp[i-][] + a[i];
                     else dp[i][] = dp[i-][] + a[i],dp[i][] = dp[i-][];
                 }
             }
             else{
                 if(s[i-] == '?'){
                     if(s[i] == '') dp[i][] = max(dp[i-][],dp[i-][] + a[i]);
                     else dp[i][] = max(dp[i-][] + a[i],dp[i-][]);
                 }
                 else{
                     if(s[i] == s[i-]) dp[i][s[i]-''] = dp[i-][s[i-]-''];
                     else dp[i][s[i]-''] = dp[i-][s[i-]-''] + a[i];
                 }
             }
         //    printf("dp[%d][0] = %d   dp[%d][1] = %d\n",i,dp[i][0],i,dp[i][1]);
         }
         printf("Case #%d: ",++kase);
         if(s[n] == '?') printf("%d\n",max(dp[n][],dp[n][]));
         else printf("%d\n",dp[n][s[n]-'']);
     }
     return ;
 }

话说比赛的时候，题目的意思都没有读懂------

诶---

加油啊---goooooo---