HDU 1176 免费馅饼——DP

#include <cstdio>
#include <cstring>
#include <iostream>
#include <algorithm>

using namespace std;

const int maxn = 1e5 + 10;

int n, dp[maxn][15];

int main()
{
    while (scanf("%d", &n) == 1 && n) {
        memset(dp, 0, sizeof(dp));
        int t = 0;
        for (int i = 0; i < n; i++) {
            int a, b; scanf("%d %d", &a, &b);
            dp[b][a + 1]++;
            t = max(t, b);
        }
        for (int i = t; i >= 0; i--) {
            for (int j = 1; j <= 11; j++) {
                dp[i][j] += max(dp[i + 1][j], max(dp[i + 1][j + 1], dp[i + 1][j - 1]));
            }
        }
        printf("%d\n", dp[0][6]);
    }
    return 0;
}