HDU 1176 免费馅饼

http://acm.hdu.edu.cn/showproblem.php?pid=1176

数塔问题的变形.....(算不上变形吧..

#include <stdio.h>
#include <string.h>
#define maxn 100005
int ans[maxn][13], dp[maxn][13];
int max(int a, int b, int c)
{
    return (a > b ? a : b) > c ? (a > b ? a : b) : c;
}
int main()
{
    int i, j, n, x, t, m, now;
    while(~scanf("%d",&n),n)
    {
        memset(ans,0,sizeof(ans));
        memset(dp,0,sizeof(dp));
        m = 0;
        for(i = 0; i < n; i++)
        {
            scanf("%d%d",&x,&t);
            ans[t][x+1] ++;
            if(t > m) m =t;
        }
        now  = 0;
        for(i = m+1; i >= 1; i--)
        {
            for(j = 1; j <= 11; j++)
            {
                dp[i][j] = max(dp[i+1][j],dp[i+1][j-1],dp[i+1][j+1])+ans[i][j];
                if(now < dp[i][j] && 6-i <= j && j <= 6+i)  now = dp[i][j];
            }
        }
        printf("%d\n",now);
    }
    return 0;
}