背包问题的解法源代码

背包问题：有若干石块（他们的体积不同，密度相同）和一个背包体积固定，求最好的石块组合，这些石块能够被放进书包且最重。

背包问题的解法：

struct ROOTTYPE
{
int *data;
int len;
int sum;
};

ROOTTYPE solve(int a[], int length, int c)
{
int sum = 0;
ROOTTYPE root;
root.data = NULL;
root.len = 0;
root.sum = 0;
int i = 0;
for(i = 0;i < length; i++)
{
sum += a[i];
}
//如果该子集中背包中物品的体积之和已经小于背包的容积，则不用计算其子集，因为子集必不是最优解

if(sum <= c)
{
root.data = a;
root.len = length;
root.sum = sum;
return root;
}
for (i = 0; i < length; i++)
{
int *data = new int[length-1];
int k = 0;
ROOTTYPE tem;

//产生子集
for(int j = 0; j < length; j++)
{

if(i ==j)
{
continue;
}
data[k++] = a[j];
}
tem = solve(data, length - 1, c);

if(tem.sum > root.sum)
{
delete[] root.data;
root = tem;
}
}
return root;
}

int main(int argc, char* argv[])
{
int data[] = {4,6,14,5,6,9,8,7};
int length = 9;
int c = 35;
ROOTTYPE tem;
tem = solve(data, length - 1, c);

printf("%d/n",tem.sum);
for(int i = 0; i < tem.len; i++)
{
printf("/n%d",tem.data[i]);
}
return 0;
}