华中科大校赛预赛1606 Naive

Naive
Time Limit: 3 Sec Memory Limit: 128 MB
Submissions: 316 Solved: 36
Description
Give you a positive integer x, determine whether it is the sum of three positive cubic numbers.

Input
There’re several test cases. For each case:
Only one line containing an integer x (1≤x≤10^6)

Output
For each test case, print “Yes” if it is or “No” if it isn’t.
(See sample for more details)

Sample Input
1
3
10
Sample Output
No
Yes
Yes
HINT
Source
Problem Setter : Zhou Zhou

题意：一个数是否可以表示成3个数的立方和 3个数可以为同一个数

思路：

一开始直接暴力先输入n 再去判断n是不是符合条件结果超时了
后来换了个思维先找出符合条件的再看n在不在小水题把

[cpp]
#include<stdio.h>
#include<string.h>
int a[105];
bool flag[1000000+10];
int main()
{ www.zzzyk.com
    int i,j,k,n,mid;
    for(i=1;i<=100;i++)
        a[i]=i*i*i;
    memset(flag,0,sizeof(flag));
    for(i=1;i<=100;i++)
        for(j=i;j<=100;j++)
            for(k=j;k<=100;k++)
            {
                  mid=a[i]+a[j]+a[k];
                if(mid<=1000000)
                 flag[mid]=1;
            }
    while(scanf("%d",&n)!=EOF)
    {
        if(flag[n]) printf("Yes\n");
        else printf("No\n");
    }

    return 0;
}

补充：软件开发 , C++ ,