Solution:

• 傻逼题目，直接dp就可以了,他是求最后一次的最大值

Code:

//It is coded by Ning_Mew on 4.17#include
    
     using namespace std;const int maxn=55,maxl=1000+7;int n,sl,xl,ans=-1;int c,dp[maxn][maxl];int main(){  freopen("changingsounds.in","r",stdin);  freopen("changingsounds.out","w",stdout);  scanf("%d%d%d",&n,&sl,&xl);  memset(dp,-1,sizeof(dp));  scanf("%d",&c);  if(sl+c<=xl)dp[1][sl+c]=1;//,ans=max(ans,sl+c);  if(sl-c>=0)dp[1][sl-c]=1;//,ans=max(ans,sl-c);  for(int i=2;i<=n;i++){    scanf("%d",&c);    //cout<<"---------"<
     <
      
       =0)dp[i][j]=max(dp[i][j],dp[i-1][j-c]);      if(j+c<=xl)dp[i][j]=max(dp[i][j],dp[i-1][j+c]);      if(dp[i][j]==1&&i==n)ans=max(ans,j);      //cout<
       
        <<' '<
        
         <<' '<
         
          <