NO11——01背包

# include <stdio.h>
# include <stdlib.h>
# include <string.h>
# define max(x,y) x>y?x:y;
int v[1001];//价值
int w[1001];//重量
int dp[1001][1001];
int main()
{
    int n,m;
    while(scanf("%d%d",&m,&n)!=EOF)
    {
        memset(dp,0,sizeof(dp));//初始化
        for(int i=1; i<=n; i++)
            scanf("%d%d",&w[i],&v[i]);
        for(int i=1; i<=n; i++) // 物品数
            for(int j=m; j>=w[i]; j--) //放入背包
                dp[i][j]=max(dp[i-1][j],dp[i-1][j-w[i]]+v[i]);// 与前面对比
        printf("%d
",dp[n][m]);
    }
}

//01背包第K优解问题
struct pack
{
    int v;//体积
    int w;//价值
}node[length];

for(i = 0;i<n;i++)
{
    for(j = v;j>=node[i].v;j--)
    {
        for(d = 1;d<=k;d++)
        {
            a[d] = dp[j-node[i].v][d] + node[i].w;
            b[d] = dp[j][d];
        }
        x = y = z = 1;
        a[d] = b[d] = -1;
        while(z<=k && (x<=k || y<=k))
        {
            if(a[x]>b[y])
            dp[j][z] = a[x++];
            else
            dp[j][x] = b[y++];
            if(dp[j][z]!=dp[j][z-1])
            z++;
        }
    }
}
//dp[v][k]为第K优解，例题：HDU2639