bzoj2748:[HAOI2012]音量调节
思路:刷水有益健康。
#include<iostream> #include<cstdio> #include<cstring> #include<algorithm> #include<cmath> using namespace std; #define maxn 55 #define maxc 10000 int n,a,r,ans; int c[maxn],f[maxn][maxc]; int main(){ scanf("%d%d%d",&n,&a,&r); for (int i=1;i<=n;i++) scanf("%d",&c[i]); f[0][a]=1; for (int i=1;i<=n;i++) for (int j=0;j<=r;j++){ if (j-c[i]>=0) f[i][j]|=f[i-1][j-c[i]]; if (j+c[i]<=r) f[i][j]|=f[i-1][j+c[i]]; } ans=-1; for (int i=r;i>=0;i--) if (f[n][i]){ans=i;break;} printf("%d\n",ans); return 0; }