动态规划练习 1

题目：The Triangle (POJ 1163)

链接：http://acm.pku.edu.cn/JudgeOnline/problem?id=1163

#include <iostream>
#include <memory.h>

using namespace std;

int main(int argc, char **argv)
{
    int data[101][101];
    int sum[101][101];
    int n;

    memset(data, 0, sizeof(data));
    memset(sum, 0, sizeof(sum));

    cin >> n;
    for (int i = 1; i <= n; ++i)
    {
        for (int j = 1; j <= i; ++j)
        {
            cin >> data[i][j];
        }
    }

    sum[1][1] = data[1][1];

    for (int i = 2; i <= n; ++i)
    {
        for (int j = 1; j <= i; ++j)
        {
            if (j >=1 && j <= i - 1 && data[i][j] + sum[i - 1][j] > sum[i][j])
            {
                sum[i][j] = data[i][j] + sum[i - 1][j];
            }
            if (j - 1 >= 1 && j - 1 <= i - 1 && data[i][j] + sum[i - 1][j - 1] > sum[i][j])
            {
                sum[i][j] = data[i][j] + sum[i - 1][j - 1];
            }
        }
    }

    int max = 0;

    for (int j = 1; j <= n; ++j)
    {
        if (sum[n][j] > max)
        {
            max = sum[n][j];
        }
    }

    cout << max;

    return 0;
}