POJ.3185 The Water Bowls

1.Problem
http://poj.org/problem?id=3185

2.Idea
Flipping

3.Source

 vector<int> A(20);  
 int solve()  
 {  
      vector<int> a = A;  
      int ans = 0;  
      for (int i = 1; i < 20; i++) {  
           if (a[i - 1] == 1) {  
                //cout << i << endl;  
                a[i - 1] = 1 - a[i - 1];  
                a[i] = 1 - a[i];  
                a[i + 1] = 1 - a[i + 1];  
                ans++;  
           }  
      }  
      return ans;  
 }  
 int main()  
 {  
      for (int i = 0; i < 20; i++) {  
           cin >> A[i];  
      }  
      int ans = solve();  
      reverse(A.begin(), A.end());  
      ans = min(ans, solve());  
      cout << ans << endl;  
      return 0;  
 }