HDU 5375 Gray Code 动归

题意：给你一串不确定的二进制码，其对应的格雷码的每一位有对应的权值，问转换成的格雷码的能取到的最大权值是多少。

思路：没有思路，乱搞也AC

#pragma comment(linker, "/STACK:1000000000")
#include <iostream>
#include <cstdio>
#include <fstream>
#include <algorithm>
#include <cmath>
#include <deque>
#include <vector>
#include <queue>
#include <string>
#include <cstring>
#include <map>
#include <stack>
#include <set>
#define LL long long
#define MAXN 100005
#define INF 0x3f3f3f3f
#define eps 1e-8
using namespace std;
char s[200005];
LL a[200005];
LL f[200005][3];
int main()
{
#ifndef ONLINE_JUDGE
    freopen("in.txt", "r", stdin);
    //freopen("out.txt", "w", stdout);
#endif // OPEN_FILE
    int T;
    scanf("%d", &T);
    int cas = 1;
    while(T--){
        scanf("%s", s + 1);

        int m = strlen(s + 1);
        for(int i = 1; i <= m; i++){
            scanf("%I64d", &a[i]);
        }
        LL ans = 0;
        int last;
        memset(f, -1, sizeof(f));
        if(s[1] != '0'){
            f[1][1] = a[1];
        }
        if(s[1] != '1'){
            f[1][0] = 0;
        }
        for(int i = 2; i <= m; i++){
            if(s[i] == '0' || s[i] == '?'){
                if(f[i - 1][1] >= 0){
                    f[i][0] = max(f[i][0], f[i - 1][1] + a[i]);
                }
                if(f[i - 1][0] >= 0){
                    f[i][0] = max(f[i][0], f[i - 1][0]);
                }
            }
            if(s[i] == '1' || s[i] == '?'){
                if(f[i - 1][0] >= 0){
                    f[i][1] = max(f[i][1], f[i - 1][0] + a[i]);
                }
                if(f[i - 1][1] >= 0){
                    f[i][1] = max(f[i][1], f[i - 1][1]);
                }
            }
        }
        printf("Case #%d: %I64d
", cas++, max(f[m][1], f[m][0]));
    }
}