poj 2923 Relocation（0-1 + 状压）

题目链接：http://poj.org/problem?id=2923

Relocation

Time Limit: 1000MS Memory Limit: 65536KTotal Submissions: 3256 Accepted: 1325

Description

Emma and Eric are moving to their new house they bought after returning from their honeymoon. Fortunately, they have a few friends helping them relocate. To move the furniture, they only have two compact cars, which complicates everything a bit. Since the furniture does not fit into the cars, Eric wants to put them on top of the cars. However, both cars only support a certain weight on their roof, so they will have to do several trips to transport everything. The schedule for the move is planed like this:

1. At their old place, they will put furniture on both cars.
2. Then, they will drive to their new place with the two cars and carry the furniture upstairs.
3. Finally, everybody will return to their old place and the process continues until everything is moved to the new place.

Note, that the group is always staying together so that they can have more fun and nobody feels lonely. Since the distance between the houses is quite large, Eric wants to make as few trips as possible.

Given the weights w_i of each individual piece of furniture and the capacities C₁ and C₂ of the two cars, how many trips to the new house does the party have to make to move all the furniture? If a car has capacity C, the sum of the weights of all the furniture it loads for one trip can be at most C.

Input

The first line contains the number of scenarios. Each scenario consists of one line containing three numbers n, C₁ and C₂. C₁ and C₂ are the capacities of the cars (1 ≤ C_i ≤ 100) and n is the number of pieces of furniture (1 ≤ n ≤ 10). The following line will contain n integers w₁, …, w_n, the weights of the furniture (1 ≤ w_i ≤ 100). It is guaranteed that each piece of furniture can be loaded by at least one of the two cars.

Output

The output for every scenario begins with a line containing “Scenario #i:”, where i is the number of the scenario starting at 1. Then print a single line with the number of trips to the new house they have to make to move all the furniture. Terminate each scenario with a blank line.

Sample Input

26 12 133 9 13 3 10 117 1 1001 2 33 50 50 67 98

Sample Output

Scenario #1:2Scenario #2:3

Source

TUD Programming Contest 2006, Darmstadt, Germany

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题目大意：Emma and Erica要搬进新家，他们有两辆车，每辆车有一个最大载重量C，求最少运几次，使得所有的物品被运走

解析：        0-1 背包 + 状压，所有物品压缩成二进制，0 表示还没运， 1 表示已经运过了，

                  借鉴大牛的博客：http://blog.csdn.net/bossup/article/details/9363845

代码如下：

#include<iostream>#include<algorithm>#include<map>#include<stack>#include<queue>#include<vector>#include<set>#include<string>#include<cstdio>#include<cstring>#include<cctype>#include<cmath>#define N 11using namespace std;const int inf = 1e9;const int mod = 1<<30;const double eps = 1e-8;const double pi = acos(-1.0);typedef long long LL;int dp[1<<N], s[1<<N], a[N];int n, k;void dfs(int num, int c1, int c2, int now){    if(num > n)    {        if(!dp[now])        {            dp[now] = 1;            s[k++] = now;        }        return ;    }    if(a[num] <= c1)  dfs(num + 1, c1 - a[num], c2, (1<<num)|now);    if(a[num] <= c2)  dfs(num + 1, c1, c2 - a[num], (1<<num)|now);    dfs(num + 1, c1, c2, now);}int main(){    int t, i, j, c1, c2, cnt = 0;    cin >> t;    while(t--)    {        scanf("%d%d%d", &n, &c1, &c2);        for(i = 0; i < n; i++) scanf("%d", &a[i]);//必须从0输入为后面各种状态做准备        k = 0;        memset(dp, 0, sizeof(dp));        dfs(0, c1, c2, 0);        memset(dp, 0x3f, sizeof(dp));        dp[0] = 0;        for(i = 0; i < 1<<n; i++)        {            for(j = 0; j < k; j++)            {                if(s[j]&i) continue;                int now = s[j]|i;                dp[now] = min(dp[now], dp[i] + 1);            }        }        printf("Scenario #%d:\n", ++cnt);        printf("%d\n\n", dp[(1<<n) - 1]);    }    return 0;}