OJ-Problems-Source/VIJOS/1317.cpp
2016-05-24 14:53:04 +08:00

48 lines
915 B
C++

#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <algorithm>
using namespace std;
/// 0-1背包问题(一维数组空间优化)
namespace Package1_SpaceOptimized
{
const int MAXM = 30000 + 5;
const int MAXN = 25 + 5;
int ldp[MAXM];
int w[MAXN];
int v[MAXN];
int N,M;
void solve()
{
for(int i=1;i<=N;i++)
{
for(int j=M;j>=1;j--)///从M到1逆序循环
{
int a=ldp[j];
int b=-1;
if(j-w[i]>=0) b=ldp[j-w[i]]+v[i];
ldp[j]=max(a,b);
}
}
printf("%d\n",ldp[M]);
}
int main()
{
scanf("%d %d",&M,&N);
for(int i=1;i<=N;i++)
{
scanf("%d %d",&w[i],&v[i]);
v[i]=w[i]*v[i];
}
solve();
return 0;
}
}
int main()
{
return Package1_SpaceOptimized::main();
}