【HDOJ】4972 A simple dynamic programming problem

水题。

 #include <cstdio>
 #include <cstring>
 #include <cstdlib>

 int abs(int x) {
     return x< ? -x:x;
 }

 int main() {
     int t, n;
     int cur, past;
     __int64 ans;
     bool flag;

     #ifndef ONLINE_JUDGE
         freopen("data.in", "r", stdin);
     #endif

     scanf("%d", &t);
     for (int i=; i<=t; ++i) {
         scanf("%d", &n);
         flag = true;
         past = ;
         ans = ;
         while (n--) {
             scanf("%d", &cur);
             if (!flag)
                 continue;
             if (abs(cur-past)> || (cur==past && cur!=)) {
                 flag = false;
                 continue;
             }
             if (past == )
                 ans *= ;
             if (cur == )
                 ans /= ;
             if ((cur== && past==) || (cur== && past==))
                 ans += ;
             past = cur;
         }
         if (!flag)
             printf("Case #%d: 0\n", i);
         else
             printf("Case #%d: %I64d\n", i, ans);
     }

     return ;
 }