C :

#include<stdio.h>

struct Goods{
	int v;//价格
	int p;//重要度
}list[25];

int max(int a,int b){
	return a>b?a:b;
}

int dp[30000];

int main(){
	int i,j,N,m;
	scanf("%d%d",&N,&m);
	for(i=1;i<=m;i++){
		scanf("%d%d",&list[i].v,&list[i].p);
	}
	for(j=0;j<N;j++){
		dp[j]=0;
	}
	for(i=1;i<=m;i++){
		for(j=N;j>list[i].v;j--){
			dp[j]=max(dp[j],dp[j-list[i].v]+list[i].p*list[i].v);
		}
	}
	printf("%d",dp[N]);
	return 0;
}

C++ :

#include<iostream>
#include<string>
#include<cstdlib>
#include<cstdio>
#include<cstring>
using namespace std;
int a[20000],b[20000],c[40000];
int main()
{
 int i,m,n,j,k;
 cin>>m>>n;
 for (i=1;i<=n;++i)
  cin>>a[i]>>b[i];
 for (i=1;i<=n;++i)
  for (j=m;j>=a[i];--j)
   if (c[j-a[i]]+a[i]*b[i]>c[j]) c[j]=c[j-a[i]]+a[i]*b[i];
 cout<<c[m];
 return 0;
}

Pascal :

var i,j,k,n,t:longint;
  v,p:array[0..25] of longint;
  f:array[0..100000] of longint;
function max(a,b:longint):longint;
  begin
    if a>b then max:=a else max:=b;
  end;
begin
 // assign(input,'happy.in');
  //r/eset(input);
 // assign(output,'happy.out');
  //rewrite(output);
  readln(k,n);
  for i:=1 to n do  readln(v[i],p[i]);
  fillchar(f,sizeof(f),0);
  for i:=1 to n do
    for j:=k downto v[i] do
    f[j]:=max(f[j],f[j-v[i]]+v[i]*p[i]);
  writeln(f[k]);
  //close(input);close(output);
end.