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
1 #pragma comment(linker, "/STACK:1000000000") 2 #include <iostream> 3 #include <cstdio> 4 #include <fstream> 5 #include <algorithm> 6 #include <cmath> 7 #include <deque> 8 #include <vector> 9 #include <queue> 10 #include <string> 11 #include <cstring> 12 #include <map> 13 #include <stack> 14 #include <set> 15 #define LL long long 16 #define MAXN 100005 17 #define INF 0x3f3f3f3f 18 #define eps 1e-8 19 using namespace std; 20 char s[200005]; 21 LL a[200005]; 22 LL f[200005][3]; 23 int main() 24 { 25 #ifndef ONLINE_JUDGE 26 freopen("in.txt", "r", stdin); 27 //freopen("out.txt", "w", stdout); 28 #endif // OPEN_FILE 29 int T; 30 scanf("%d", &T); 31 int cas = 1; 32 while(T--){ 33 scanf("%s", s + 1); 34 35 int m = strlen(s + 1); 36 for(int i = 1; i <= m; i++){ 37 scanf("%I64d", &a[i]); 38 } 39 LL ans = 0; 40 int last; 41 memset(f, -1, sizeof(f)); 42 if(s[1] != '0'){ 43 f[1][1] = a[1]; 44 } 45 if(s[1] != '1'){ 46 f[1][0] = 0; 47 } 48 for(int i = 2; i <= m; i++){ 49 if(s[i] == '0' || s[i] == '?'){ 50 if(f[i - 1][1] >= 0){ 51 f[i][0] = max(f[i][0], f[i - 1][1] + a[i]); 52 } 53 if(f[i - 1][0] >= 0){ 54 f[i][0] = max(f[i][0], f[i - 1][0]); 55 } 56 } 57 if(s[i] == '1' || s[i] == '?'){ 58 if(f[i - 1][0] >= 0){ 59 f[i][1] = max(f[i][1], f[i - 1][0] + a[i]); 60 } 61 if(f[i - 1][1] >= 0){ 62 f[i][1] = max(f[i][1], f[i - 1][1]); 63 } 64 } 65 } 66 printf("Case #%d: %I64d\n", cas++, max(f[m][1], f[m][0])); 67 } 68 }
