hdu--1506--矩阵求和<stack>

 1 #include <iostream>
 2 #include <algorithm>
 3 using namespace std;
 4 
 5 typedef long long LL;
 6 const int size = 100010;
 7 int Left[size];
 8 int Right[size];
 9 LL h[size];
10 
11 int main()
12 {
13     int i , n;
14     LL ans , area;
15     while( cin >> n && n )
16     {
17         ans = 0;
18         h[0] = h[n+1] = -1;
19         for( i = 1 ; i<=n ; i++ )
20         {
21             cin >> h[i];
22             Left[i] = Right[i] = i;
23         }
24         for( i = 2 ; i<=n ; i++ )
25         {
26             while( h[ Left[i]-1 ] >= h[i] )
27             {
28                 Left[i] = Left[ Left[i]-1 ];
29             }
30         }
31         for( i = n-1 ; i>=1 ; i-- )
32         {
33             while( h[ Right[i]+1 ] >= h[i] )
34             {
35                 Right[i] = Right[ Right[i]+1 ];
36             }
37         }
38         for( i = 1 ; i<=n ; i++ )
39         {
40             area = (LL) h[i] * ( Right[i] - Left[i] + 1 );
41             ans = max( ans , area );
42         }    
43         cout << ans << endl;
44     }
45     return 0;
46 }

 1 #include <iostream>
 2 #include <stack>
 3 #include <algorithm>
 4 using namespace std;
 5 
 6 typedef long long LL;
 7 const int size = 100010;
 8 LL h[size];
 9 struct data
10 {
11     int w;
12     LL h;
13     data( int x , LL y )
14     {
15         w = x;
16         h = y;
17     }
18 };
19 stack<data>s;
20 
21 int main()
22 {
23     cin.sync_with_stdio(false);
24     int n , totalW;
25     LL area , ans;
26     while( cin >> n && n )
27     {
28         for( int i = 0 ; i<n ; i++ )
29         {
30             cin >> h[i];
31         }
32         ans = h[n] = 0;
33         while( !s.empty() )
34             s.pop();
35         for( int i = 0 ; i<=n ; i++ )
36         {
37             if( s.empty() || h[i] > s.top().h )
38             {
39                 s.push( data( 1,h[i] ) );
40             }
41             else if( h[i] == s.top().h )
42             {
43                 s.top().w ++;
44             }
45             else
46             {
47                 totalW = 0;
48                 while( !s.empty() && h[i] < s.top().h )
49                 {
50                     totalW += s.top().w;
51                     area = (LL)totalW * s.top().h;
52                     ans = max( ans , area );
53                     s.pop();
54                 }
55                 s.push( data( totalW+1,h[i] ) );
56             }
57         }
58         cout << ans << endl;
59     }
60     return 0;
61 }