题意:有n个商店,有m金钱,一个商店买x件商品需要x*w[i]的金钱,得到a[i] * x + b[i]件商品(x > 0),问最多能买到多少件商品
01背包+完全背包:首先x == 1时,得到a[i] + b[i],若再买得到的是a[i],那么x == 1的情况用01背包思想,x > 1时就是在01的基础上的完全背包。背包dp没刷过专题,这么简单的题也做不出来:(
/************************************************ * Author :Running_Time * Created Time :2015-8-20 12:35:33 * File Name :E.cpp ************************************************/ #include <cstdio> #include <algorithm> #include <iostream> #include <sstream> #include <cstring> #include <cmath> #include <string> #include <vector> #include <queue> #include <deque> #include <stack> #include <list> #include <map> #include <set> #include <bitset> #include <cstdlib> #include <ctime> using namespace std; #define lson l, mid, rt << 1 #define rson mid + 1, r, rt << 1 | 1 typedef long long ll; const int MAXN = 1e3 + 10; const int MAXM = 2e3 + 10; const int INF = 0x3f3f3f3f; const int MOD = 1e9 + 7; int a[MAXN], b[MAXN], w[MAXN]; int dp[MAXM]; int main(void) { //HDOJ 5410 CRB and His Birthday int T; scanf ("%d", &T); while (T--) { int m, n; scanf ("%d%d", &m, &n); for (int i=1; i<=n; ++i) { scanf ("%d%d%d", &w[i], &a[i], &b[i]); } memset (dp, 0, sizeof (dp)); for (int i=1; i<=n; ++i) { for (int j=m; j>=w[i]; --j) { dp[j] = max (dp[j], dp[j-w[i]] + a[i] + b[i]); } for (int j=w[i]; j<=m; ++j) { dp[j] = max (dp[j], dp[j-w[i]] + a[i]); } } printf ("%d\n", dp[m]); } return 0; }