Cod sursa(job #692842)
#include<cstdio>
using namespace std;
int n,w,a[3][5010],e[1010],p[1010],sum,i,j;
int min(int a,int b)
{
if(a<b)
{
return a;
}
else
{
if(b==0)
{
return a;
}
else
{
return b;
}
}
}
int main()
{
freopen("energii.in","r",stdin);
freopen("energii.out","w",stdout);
scanf("%d%d",&n,&w);
for(i=1;i<=n;i++)
{
scanf("%d%d",&e[i],&p[i]);
sum+=e[i];
}
if(sum<w)
printf("%d",-1);
else
{
for(i=1;i<=e[1];i++)
{
a[1][i]=p[1];
}
for(i=2;i<=n;i++)
{
for(j=1;j<=w;j++)
{
if(j-e[i]<1)
{
a[i%2][j]=min(p[i],a[(i-1)%2][j]);
}
else
{
a[i%2][j]=min(a[(i-1)%2][j-e[i]]+p[i],a[(i-1)%2][j]);
if(a[i%2][j]<j)
{
a[i%2][j]=0;
}
}
}
}
}
printf("%d",a[n%2][w]);
return 0;
}