标签:+= 最大 rsa printf break while sar 标记 specific
InputEmployees are numbered from 1 to N. A first line of input contains a number N. 1 <= N <= 6 000. Each of the subsequent N lines contains the conviviality rating of the corresponding employee. Conviviality rating is an integer number in a range from -128 to 127. After that go T lines that describe a supervisor relation tree. Each line of the tree specification has the form:
L K
It means that the K-th employee is an immediate supervisor of the L-th employee. Input is ended with the line
0 0OutputOutput should contain the maximal sum of guests‘ ratings.
Sample Input
7 1 1 1 1 1 1 1 1 3 2 3 6 4 7 4 4 5 3 5 0 0
Sample Output
5
题解:树形DP。对于每个人,我们储存下比他职位低的下标,并对比他职位低的人打上标记代表这个人有上司。dp[i][1]代表选i这个人,dp[i][0]代表不选这个人,然后从底层开始,对上一层dp[x][1]+=dp[x-1][0];
dp[x][0]+=max(dp[x-1][1],dp[x-1][0]);
然后最大值为: max(dp[root][1],dp[root][0]);root为没有标记的那个人,即没有任何下属的人;
参考代码为:
#include<iostream> #include<cstdio> #include<cstring> #include<cmath> #include<algorithm> #include<queue> #include<stack> #include<map> #include<vector> #include<cstdlib> #include<set> using namespace std; const int maxn=1e4+10; int N,u,v,w[maxn],vis[maxn],dp[maxn][2]; vector<int> vec[maxn]; void solve(int x) { for(int i=0;i<vec[x].size();i++) { solve(vec[x][i]); dp[x][1]+=dp[vec[x][i]][0]; dp[x][0]+=max(dp[vec[x][i]][0],dp[vec[x][i]][1]); } } int main() { while(~scanf("%d",&N)) { for(int i=0;i<=N;i++) vec[i].clear(); memset(vis,0,sizeof vis); memset(dp,0,sizeof dp); for(int i=1;i<=N;i++) scanf("%d",w+i); for(int i=1;i<=N;i++) dp[i][1]=w[i]; while(scanf("%d%d",&u,&v), u+v) { vec[v].push_back(u); vis[u]=1; } int flag; for(int i=1;i<=N;i++) { if(!vis[i]) { solve(i); flag=i; break; } } int Max=max(dp[flag][1],dp[flag][0]); printf("%d\n",Max); } return 0; }
标签:+= 最大 rsa printf break while sar 标记 specific
原文地址:https://www.cnblogs.com/songorz/p/9409726.html