题目链接

https://www.nowcoder.com/acm/contest/85/G

思路

按照题解上的方式 存取数据

然后DP一下 就可以了

AC代码

#include <cstdio>

#include <cstring>

#include <ctype.h>

#include <cstdlib>

#include <cmath>

#include <climits>

#include <ctime>

#include <iostream>

#include <algorithm>

#include <deque>

#include <vector>

#include <queue>

#include <string>

#include <map>

#include <stack>

#include <set>

#include <numeric>

#include <sstream>

#include <iomanip>

#include <limits>

using namespace std;

typedef long long ll;

typedef unsigned long long ull;

typedef pair <int, int> pii;

typedef pair <ll, ll> pll;

const double PI  = 3.14159265358979323846264338327;

const double E   = exp(1);

const double eps = 1e-6;

const int INF    = 0x3f3f3f3f;

const int maxn   = 3e3 + 5;

const int MOD    = 1e9 + 7;

int Map[maxn][maxn], Cur[maxn], dp[maxn][maxn];

int main()

{

    int n;

    scanf("%d", &n);

    memset(Map, 0xc0, sizeof(Map));

    memset(Cur, 0, sizeof(Cur));

    memset(dp, 0, sizeof(dp));

    int vis = 1 + (4 * (n - 1));

    int cur = 2 * n - 1;

    int i, j;

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

        Cur[i] = i + 1;

    int opt[2];

    opt[i % 2] = n - 1;

    opt[!(i % 2)] = n;

    int flag = i % 2;;

    for ( ; i < (vis - n); i++, flag = !flag)

        Cur[i] = opt[flag];

    for (j = n ; i < vis; i++, j--)

        Cur[i] = j;

    vector <int> v[vis];

    int temp;

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

    {

        for (j = 0; j < Cur[i]; j++)

        {

            scanf("%d", &temp);

            v[i].push_back(temp);

        }

    }

    int len = cur/2 + 1;

    flag = 0;

    for (i = 0, j = n; i < len; i++, j++)

    {

        for (int l = 0, k = flag; l < j; l++, k++)

        {

            Map[i][l] = v[k][v[k].size() - 1];

            v[k].pop_back();

            if (v[k].size() == 0)

                flag++;

        }

    }

    for (j -= 2; i < cur; i++, j--)

    {

        for (int l = (cur - j), k = flag; l < cur; l++, k++)

        {

            Map[i][l] = v[k][v[k].size() - 1];

            v[k].pop_back();

            if (v[k].size() == 0)

                flag++;

        }

    }

    dp[0][0] = Map[0][0];

    for (i = 1; i < cur; i++)

    {

        dp[0][i] = dp[0][i - 1] + Map[0][i];

        dp[i][0] = dp[i - 1][0] + Map[i][0];

    }

    for (i = 1; i < cur; i++)

    {

        for (j = 1; j < cur; j++)

            dp[i][j] = max(max(dp[i - 1][j], dp[i][j - 1]), dp[i - 1][j - 1]) + Map[i][j];

    }

    cout << dp[cur - 1][cur - 1] << endl;

}