POJ 2184 DP 01背包+完全背包

链接：

http://poj.org/problem?id=2184

代码：

 1 #include <map>
 2 #include <set>
 3 #include <cmath>
 4 #include <queue>
 5 #include <stack>
 6 #include <cstdio>
 7 #include <string>
 8 #include <vector>
 9 #include <cstdlib>
10 #include <cstring>
11 #include <sstream>
12 #include <iostream>
13 #include <algorithm>
14 #include <functional>
15 using namespace std;
16 #define rep(i,a,n) for (int i=a;i<n;i++)
17 #define per(i,a,n) for (int i=n-1;i>=a;i--)
18 #define all(x) (x).begin(),(x).end()
19 #define pb push_back
20 #define mp make_pair
21 #define lson l,m,rt<<1  
22 #define rson m+1,r,rt<<1|1 
23 typedef long long ll;
24 typedef vector<int> VI;
25 typedef pair<int, int> PII;
26 const ll MOD = 1e9 + 7;
27 const int INF = 0x3f3f3f3f;
28 const int MAXN = 2e5 + 7;
29 // head
30 
31 int n;
32 int s[110], f[110];
33 int dp[MAXN];
34 
35 int main() {
36     int n;
37     cin >> n;
38     rep(i, 1, n + 1) cin >> s[i] >> f[i];
39     rep(i, 0, MAXN) dp[i] = -INF;
40     dp[100000] = 0;
41     rep(i, 1, n + 1) {
42         if (s[i] < 0 && f[i] < 0) continue;
43         if (s[i] > 0) {
44             per(j, s[i], 200001) if (dp[j - s[i]] > -INF)
45                 dp[j] = max(dp[j], dp[j - s[i]] + f[i]);
46         }
47         else {
48             rep(j, s[i], s[i] + 200001) if (dp[j - s[i]] > -INF)
49                 dp[j] = max(dp[j], dp[j - s[i]] + f[i]);
50         }
51     }
52     int ans = 0;
53     rep(i, 100000, 200001) if (dp[i] >= 0)
54         ans = max(ans, dp[i] + i - 100000);
55     cout << ans << endl;
56     return 0;
57 }

 

posted @ 2017-04-18 16:01  Flowersea  阅读(214)  评论(0)    收藏  举报