递推DP POJ 1163 The Triangle

 1 /*
 2     数塔
 3     自底向上
 4 */
 5 #include <cstdio>
 6 #include <iostream>
 7 #include <cstring>
 8 #include <string>
 9 #include <algorithm>
10 #include <cmath>
11 using namespace std;
12 
13 const int MAXN = 100 + 10;
14 const int INF = 0x3f3f3f3f;
15 int a[MAXN][MAXN];
16 int dp[MAXN][MAXN];
17 
18 void work(int n)
19 {
20     for (int i=n-1; i>=1; --i)
21     {
22         for (int j=1; j<=i; ++j)
23         {
24             dp[i][j] += max (dp[i+1][j], dp[i+1][j+1]);
25         }
26     }
27     printf ("%d\n", dp[1][1]);
28 }
29 
30 int main(void)        //POJ 1163 The Triangle
31 {
32     //freopen ("H.in", "r", stdin);
33 
34     int n;
35     while (~scanf ("%d", &n))
36     {
37         for (int i=1; i<=n; ++i)
38         {
39             for (int j=1; j<=i; ++j)
40             {
41                 scanf ("%d", &a[i][j]);
42                 dp[i][j] = a[i][j];
43             }
44         }
45         work (n);
46     }
47 
48     return 0;
49 }