hdu 2084

//Time Limit Exceeded                              普通递归     自顶向下

#include <iostream>
#define N 105      
#include<string.h>
using namespace std;
int a[N][N];
int n;
int max(int x, int y)
{  return x>y?x:y   ;      }

int maxsum(int i,int j)
{
 if(i==n-1)  return a[i][j];                                                  //最后一行   终止条件  出口
 return a[i][j]+max(maxsum(i+1,j),maxsum(i+1,j+1));                        //a[i][j]   自己本身       ，，，，，
}                                                                                             //下一行   其中的 最大值      max(  maxsum(i+1,j)   ,  maxsum(i+1,j+1)    )

int main()
{
  int c ;
 int i,j;
 cin>>c;
 while(c--)
 {
  cin>>n ;
  for(i=0;i<n;i++)
    for(j=0;j<=i;j++)  cin>>a[i][j];
   
  
         cout<<maxsum(0,0)<<endl;
 }
 
}

#include <iostream>
#define N 105      
#include<string.h>
using namespace std;
int a[N][N];
int n;
int s[N][N];
int max(int x, int y)
{  return x>y?x:y   ;      }

int maxsum(int i,int j)
{
 if(i==n-1)            return s[i][j]=a[i][j];
                    return s[i][j]=a[i][j]+max(maxsum(i+1,j),maxsum(i+1,j+1));                                     //不知道是否算过
}

int main()
{
  int c ;
 int i,j;
 cin>>c;
 while(c--)
 {
  cin>>n ;
  for(i=0;i<n;i++)
    for(j=0;j<=i;j++)  cin>>a[i][j];
   
  
         cout<<maxsum(0,0)<<endl;
 }
 
}

******************************************************************************88

                     记忆式搜索

#include <iostream>
#define N 105      
#include<string.h>
using namespace std;
int a[N][N];
int n;
int s[N][N];
int max(int x, int y)
{  return x>y?x:y   ;      }

int maxsum(int i,int j)
{
 if(i==n-1)    return s[i][j]=a[i][j];
     else if(s[i][j]!=-1)  return s[i][j];
     return s[i][j]=a[i][j]+max(maxsum(i+1,j),maxsum(i+1,j+1));
}

int main()
{
  int c ;
 int i,j;
 cin>>c;
 while(c--)
 {
    memset(s,-1,sizeof(s));
  cin>>n ;
  for(i=0;i<n;i++)
    for(j=0;j<=i;j++)  cin>>a[i][j];
   
  
         cout<<maxsum(0,0)<<endl;
 }
 
}

hdu 2084   记忆式搜索

#include <iostream>

#include <cstring>

#define N 100

using namespace std;

int a[N][N],n,s[N][N];

int maxsum(int i,int j)

{ if (i==n-1) return s[i][j]=a[i][j];

else if (s[i][j]!=-1) return s[i][j];  

else return s[i][j]=a[i][j]+max(maxsum(i+1,j),maxsum(i+1,j+1));

}

int main(int argc, char *argv[])

{ int i,j,c;

cin>>c;

while (c--)

{ cin>>n;

memset(s,-1,sizeof(s));

for (i=0;i<n; i++)

  for (j=0;j<=i; j++) cin>>a[i][j];

   cout<<maxsum(0,0)<<endl;

}

return 0;

}

 

 

 

 

 

 

 

 

 

 

********************************************************************************************************************************************************************************************

 

DP动态规划

 

 自底而上

 

 

#include <iostream>
#define N 100
using namespace std;
int a[N][N],n;
int dp( )
{ int i,j;
for (i=n-2;i>=0; i--)
  for (j=0; j<=i; j++)
    a[i][j]  +  =max(  a[i+1][  j ] , a[i+1][ j+1 ]  );
}

int main(int argc, char *argv[])
{
  int i,j,c;
cin>>c;
while (c--)
{          cin>>n;
   for (i=0;i<n; i++)
      for (j=0;j<=i; j++)       cin>>a[i][j];
        dp();
   cout<<a[0][0]<<endl;
}
return 0;
}