Description
7Figure 1 shows a number triangle. Write a program that calculates the highest sum of numbers passed on a route that starts at the top and ends somewhere on the base. Each step can go either diagonally down to the left or diagonally down to the right.
3 8
8 1 0
2 7 4 4
4 5 2 6 5
(Figure 1)
Input
Your program is to read from standard input. The first line contains one integer N: the number of rows in the triangle. The following N lines describe the data of the triangle. The number of rows in the triangle is > 1 but <= 100. The numbers in the triangle, all integers, are between 0 and 99.
Output
Your program is to write to standard output. The highest sum is written as an integer.
Sample Input
5 7 3 8 8 1 0 2 7 4 4 4 5 2 6 5
Sample Output
30
题目大意：
求从最上面到最下面的最大和；参照Figure 1图
#include<iostream>
using namespace std;
int main()
{
int n,aa[100][100];
cin>>n;
for(int i=0;i<n;i++)
for(int j=0;j<=i;j++)
cin>>aa[i][j];
for(int i=n-2;i>=0;i--)//为什么要n-2呢？？
//思路是从倒数第一行开始把值加到上面一行，这样得到的aa[0][0]一定是最大值
{
for(int j=0;j<=i;j++)
{
aa[i][j]+=max(aa[i+1][j],aa[i+1][j+1]);
}
}
cout<<aa[0][0]<<endl;
return 0;
}
例如：
5
7
3 8
8 1 0
2 7 4 4
4 5 2 6 5
执行之后结果：
30
23 8
20 1 0
7 12 4 4
4 5 2 6 5
