学步园

原题链接：http://acm.nyist.net/JudgeOnline/problem.php?pid=613

AC代码：

#include<stdio.h>
#include<stdlib.h>
#include<iostream>
#include<cstring>
#include<algorithm>

using namespace std;
const int Max = 100000 +10;

int dp[Max][12];
int MAX (int a ,int b ,int c)
{
    return max(max(a,b),c);
}
void dp_find(int n)
{
    int i,j;
    for(i = 1;i <= n;i ++ )
    {
        for(j = 1;j <= 11;j ++)
        {
            int ans = MAX(dp[i-1][j-1],dp[i-1][j],dp[i-1][j+1]);
            dp[i][j] += ans;
        }
    }
}
void display(int n)
{
    int i,j;
    for(i = 1;i <= n;i ++ )
    {
        for(j = 1;j <= 11;j ++)
        {
            printf("%d  ",dp[i][j]);
        }
        printf("\n");
    }
}
int main()
{
    int i,j,k,n,x,y;
    int beg,end;
    while(scanf("%d",&n)&&n)
    {
        int ans = 0;
        j = 1;
        memset(dp,0,sizeof(dp));
        k = 6;
        for(i = 0;i < n; i++)
        {
            scanf("%d%d",&x,&y);
            x++;
            if(x >= 12) continue;
            if(x >= k - y && x <= k + y)
            {
               dp[y][x] ++ ;
               j = max(j,y);
            }
        }
        dp_find(j);
        for(i = 1;i <= 11;i ++)
            ans = max(ans,dp[j][i]);
        printf("%d\n",ans);

    }
}