C :

#include<stdio.h>
int max(int a,int b)
{
    return(a > b? a:b);
}
int a[1005][1005];
int main()
{
    int i,j,n;
    scanf("%d",&n);
    for(i = 1;i <= n;i++)
        for(j = 1;j <= i;j++)
        scanf("%d",&a[i][j]);

    for(i = n;i >= 2;i--)//当i<i时 越界
        for(j = 1;j < i;j++)//当j=i时 越界
        a[i-1][j] = a[i-1][j]+max(a[i][j],a[i][j+1]);//递归
    printf("%d\n",a[1][1]);
    return 0;
}

C++ :

#include<iostream>
#include<algorithm>
using namespace std;
const int N(1005);
long long a[N][N],f[N][N]={0};
int main()
{
    //ifstream cin("exam1.in");
    //ofstream cout("exam1.out");
    int n;
    cin>>n;
    for (int i=1;i<=n;i++)
        for (int j=1;j<=i;j++)
            cin>>a[i][j];
    f[1][1]=a[1][1];
    for (int i=2;i<=n;i++)
        for (int j=1;j<=i;j++)
            f[i][j]=max(f[i-1][j-1],f[i-1][j])+a[i][j];
    long long ans=f[n][1];
    for (int j=1;j<=n;j++)
        ans=max(ans,f[n][j]);
    cout<<ans<<endl;
    //system("pause");
    return 0;
}

Pascal :

Program TK2596;
uses math;
var i,j,n:longint; 
    a,f:array[0..1000,0..1000]of longint;

Begin 
	readln(n);
	for i:=1 to n do for j:=1 to i do 
		read(a[i][j]);
	for i:=n downto 1 do for j:=1 to i do begin 
		if i=n then f[i][j]:=a[i][j]
			else f[i][j]:=a[i][j]+max(f[i+1][j],f[i+1][j+1]);
	end;
	writeln(f[1][1]);
End.