CF 256D. Good Sequences(DP)

题目链接

主要是标记前面素数的最大的DP值，要认真一些。没想到居然写了一个很难发现的错误。

#include <cstdio>
#include <cstring>
#include <string>
#include <cmath>
#include <ctime>
#include <cstdlib>
#include <iostream>
using namespace std;
int o[200001];
int prim[200001];
int p[200001];
int sp[200001];
int flag[200001];
int main()
{
    int i,j,n,num = 1;
    int temp,maxz;
    for(i = 2; i <= 100000; i ++)
    {
        if(!o[i])
        {
            sp[i] = num;
            for(j = i+i; j <= 100000; j += i)
                o[j] = 1;
            prim[num++] = i;
        }
    }
    scanf("%d",&n);
    for(i = 0; i < n; i ++)
        scanf("%d",&p[i]);
    if(n == 1)
    {
        printf("1
");
        return 0;
    }
    for(i = 0; i < n; i ++)
    {
        maxz = 0;
        temp = p[i];
        for(j = 1; j < 200; j ++)
        {
            if(temp == 1) break;
            if(temp%prim[j] == 0)
            {
                maxz = max(maxz,flag[j]);
                while(temp%prim[j] == 0)
                {
                    temp /= prim[j];
                }
            }
        }
        if(temp != 1)
        maxz = max(maxz,flag[sp[temp]]);
        temp = p[i];
        for(j = 1; j < 200; j ++)
        {
            if(temp == 1) break;
            if(temp%prim[j] == 0)
            {
                flag[j] = maxz + 1;
                while(temp%prim[j] == 0)
                {
                    temp /= prim[j];
                }
            }
        }
        if(temp != 1)
        flag[sp[temp]] = maxz + 1;
    }
    maxz = 0;
    for(i = 1;i < num;i ++)
    {
        maxz = max(maxz,flag[i]);
    }
    printf("%d
",maxz);
    return 0;
}