Dima and Salad CodeForces - 366C 背包DP

#include <iostream>
#include <cstdio>

using namespace std;

const int N = 1e4+10;
const int inf = 1e8;
int dp
,dp2
;
int a[110],b[110];
int n,k;
int main()
{
int num;
scanf("%d%d",&n,&k);
for ( int i=1; i<=n; i++ ) scanf("%d",&a[i]);
for ( int i=1; i<=n; i++ ) scanf("%d",&b[i]);
for ( int i=1; i<=10000; i++ ) dp[i] = dp2[i] = -inf ;

for ( int i=1;i<=n;i++ ) {
num = a[i]-b[i]*k;
if ( num>=0 ) {
for ( int j=10000; j>=num; j-- ) dp[j] = max( dp[j] , dp[j-num]+a[i] );
}
else {
num = -num;
for ( int j=10000; j>=num; j-- ) dp2[j] = max( dp2[j] , dp2[j-num]+a[i] );
}
}
int ans = -1;
for ( int i=10000; i>=0; i-- )
ans  = max( ans , dp[i]+dp2[i] );
if ( ans<=0 ) ans = -1 ;
cout<<ans<<endl;
return 0;
}