题目不难，暴力地dp一下就好，但是不知道我WA在哪里了，对拍了好多的数据都没找出错误= =。估计又是哪里小细节写错了QAQ。。思路是用dp[i][j]表示已经选了i个，差值为j的最大和。转移的话暴力枚举当前选那个即可。代码如下（WA的，以后有机会再找找错在哪里吧0.0）：
1 #include2 #include 3 #include 4 #include 5 using namespace std; 6 const int N = 200 + 5; 7 8 int n,m; 9 int a[N],b[N];10 struct node11 {12 int now,pre,val;13 int a,b;14 }dp[20+5][800+5];15 16 set get(int x)17 {18 set S;19 for(int i=m;i>=1;i--)20 {21 S.insert(dp[i][x].now);22 x = dp[i][x].pre;23 }24 return S;25 }26 27 int main()28 {29 int kase = 1;30 while(scanf("%d%d",&n,&m) == 2)31 {32 if(n == 0 & m == 0) break;33 for(int i=1;i<=n;i++) scanf("%d%d",a+i,b+i);34 for(int i=0;i<=800;i++) dp[0][i] = (node){-1,-1,0,0,0};35 dp[0][400] = (node){ 0,-1,0,0,0};36 for(int i=1;i<=m;i++)37 {38 for(int j=0;j<=800;j++)39 {40 dp[i][j] = (node){-1,-1,0,0,0};41 for(int k=1;k<=n;k++)42 {43 int add = a[k] - b[k];44 if(j-add < 0 || j - add > 800) continue;45 int pre = j - add;46 if(dp[i-1][pre].now == -1) continue;47 int flag = 1;48 for(int p=i-1;p>=1;p--)49 {50 if(dp[p][pre].now == k)51 {52 flag = 0;53 break;54 }55 else pre = dp[p][pre].pre;56 }57 if(flag == 0) continue;58 if(dp[i-1][j - add].val + a[k]+b[k] > dp[i][j].val)59 {60 dp[i][j] = (node){k,j-add,dp[i-1][j - add].val + a[k]+b[k],61 dp[i-1][j - add].a + a[k], dp[i-1][j - add].b + b[k]};62 }63 }64 }65 }66 set S;67 int aa, bb;68 for(int add=0;add<=400;add++)69 {70 if(dp[m][400-add].now == -1 && dp[m][400+add].now == -1) continue;71 int temp = 0;72 if(dp[m][400-add].now != -1)73 {74 temp = dp[m][400-add].val;75 S = get(400-add);76 aa = dp[m][400-add].a, bb = dp[m][400-add].b;77 }78 if(dp[m][400+add].now != -1)79 {80 if(dp[m][400+add].val > temp)81 {82 S = get(400+add);83 aa = dp[m][400+add].a, bb = dp[m][400+add].b;84 }85 }86 break;87 }88 printf("Jury #%d\n",kase++);89 printf("Best jury has value %d for prosecution and value %d for defence:\n",aa,bb);90 for(set ::iterator it=S.begin();it!=S.end();it++) printf(" %d",*it);91 puts("\n");92 }93 return 0;94 }