p1 背包 tyvj1329

代码 
type list=record
     num,len:longint;
     name:string;
     end;
var n,i,j,k,long,ans:longint;
    a:array[1..20000]of list;
    f:Array[0..2000000]of longint;
    c:char;

begin
  readln(n);
  readln(c);
  readln(long);
  for i:=1 to n do
    begin
      readln(a[i].num,a[i].name);
      delete(a[i].name,1,1);
      a[i].len:=length(a[i].name);
    end;
  if c='N' then
    begin
      fillchar(f,sizeof(f),127);
      f[0]:=0;
      for i:=1 to n do
        for j:=long downto 1 do
          if f[j]>f[j-1]+a[i].num then f[j]:=f[j-1]+a[i].num;
      if f[long]>2000000 then writeln('DIY') else writeln(f[long]);
    end;
  if c='L' then
    begin
      fillchar(f,sizeof(f),127);
      f[0]:=0;
      for i:=1 to n do
        for j:=long downto a[i].len do
          if f[j]>f[j-a[i].len]+a[i].num then f[j]:=f[j-a[i].len]+a[i].num;
      if f[long]>2000000 then writeln('DIY') else writeln(f[long]);
    end;
end.

 

p2 数学 tyvj1330

#include<fstream>
#include<cmath>
//#include<iostream>
using namespace std;
ifstream cin("tyvj.txt");
ofstream cout("tyvj.out");
int n;
long long x,y=1;
int main()
{
    cin>>n;
    int num=n;
    int t=(int)sqrt((double)n);
    for (int i=2;i<=t;i++)
    {
        long long num=0;
        while ((n%i)==0) 
        {
              n/=i;
              num++;
        }
        if (num%2==1) y*=i;
    }
    y*=n;
    x=num+y;
    long long d=num*y;
    long long dd=2*(long long)sqrt((double)d);
    x+=dd;
    cout<<x<<endl;
    return 0;
}
p3 dfs tyvj1331

//#include<fstream>
#include<iostream>
#include<cmath>
#include<cstring>
#define maxe 100010
using namespace std;
//ifstream cin("tyvj.txt");
//ofstream cout("tyvj.out");
int n,o=0;
struct node
{
       int x,n;
}e[maxe];
int k[maxe],f[maxe],ans,b[maxe];
bool v[maxe];
int abs(int x)
{
    if (x<0) x=-x;
    return x;
}
void add(int x,int y)
{
     e[++o].x=y;
     e[o].n=k[x];
     k[x]=o;
}
void init()
{
     cin>>n;
     int x,y;
     for (int i=1;i<n;i++)
     {
         cin>>x>>y;
         add(x,y);
         add(y,x);
     }
}

void dfs(int x,int y)
{
     int t=k[y];
     v[y]=1;
     while (t)
     {
           if (!v[e[t].x]) {dfs(t,e[t].x);f[x]+=f[t];}
           t=e[t].n;
     }
     f[x]++;
}


int main()
{
    init();
    dfs(0,1);
    int m=n/2;
    ans=99999999;
    for (int i=1;i<=2*n;i++)
    {
        if (abs(m-f[i])<ans)
        {
                            memset(b,0,sizeof(b));
                            ans=abs(m-f[i]);
                            b[0]=1;
                            b[1]=i;
        }else 
          if ((abs(m-f[i]))==ans)
          {
                               b[++b[0]]=i;
          }
    }
    for (int i=1;i<=b[0];i++) cout<<(b[i]+1)/2<<endl;
    return 0;
}