Fzu 2214--knapsack problem —————— "oversized backpack with 01 backpacks"

2214 knapsack problemAccept:6 Submit:9
Time limit:3000 mSec Memory limit:32768 KB problem Description

Given a set of n items, each with a weight w[i] and a value v[i], determine a-to-choose the items into a knapsack so T Hat The total weight are less than or equal to a given limit B and the total value is as large as possible. Find the maximum total value. (Note that each item can is only chosen once).

Input

The first line contains the integer T indicating to the number of test cases.

For each test case, the first line contains the integers n and B.

Following n lines provide the information of each item.

The i-th line contains the weight w[i] and the value v[i] of the i-th item respectively.

1 <= Number of test cases <= 100

1 <= N <= 500

1 <= B, W[i] <= 1000000000

1 <= v[1]+v[2]+...+v[n] <= 5000

All the inputs is integers.

Output

For each test case, output the maximum value.

Sample INPUT15 1512 101 2 sample Output15 source sixth Fujian College student Program Design contest-Replay (thanks to the organizer of Huaqiao University) topic: give you T Group of data, each group has n items, a backpack capacity B, each has a volume and value. Ask you what the maximum value of the item in this backpack is. Each item can only be put in one backpack. How to solve the problem: first of all, this is clearly seen as a 01 backpack. But the backpack is very large, and the volume of the goods is very large, but the total value is very small. Dp[i] Indicates the maximum value of a backpack capacity of I,so let's change the meaning of this dp[] array, Dp[i] represents the minimum capacity required to load value I.

#include <stdio.h> #include <algorithm> #include <string.h>using namespace std;const int maxn = 550; const int INF = 0x3f3f3f3f;int W[MAXN], v[maxn];int dp[5500];int main () {    int T, n, B;    scanf ("%d", &t);    while (t--) {        scanf ("%d%d", &n,&b);        int V = 0;        for (int i = 1; I <= n; i++) {            scanf ("%d%d", &w[i],&v[i]);            V + = V[i];        }        Memset (Dp,inf,sizeof (DP));        Dp[0] = 0;        for (int i = 1, i <= N; i++) {for            (int j = V; J >= V[i]; j--) {                Dp[j] = min (dp[j],dp[j-v[i]]+w[i]);   printf ("%d", dp[j]);            }        }        int ans = 0;        for (int i = V; I >= 0, i--) {            if (Dp[i] <= B) {                ans = i; break;            }        }        printf ("%d\n", ans);    }    return 0;}

　　

Fzu 2214--knapsack problem —————— "oversized backpack with 01 backpacks"