Acwing 1291.轻拍牛头

2020-12-26 00:28

阅读:459

标签:const   lse   scanf   暴力   out   define   stream   其他   max   

题意:

给定一个序列ai,问序列中其他数中有多少个数是它的约数

思路:

暴力求法会超时。O(n²)

最优解:先储存每个数的个数,遍历x,每个x的倍数加上x的个数

注:最后每个数的答案要-1(减去本身)

Code:

#pragma GCC optimize(3)
#pragma GCC optimize(2)
#include 
#include set>
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include using namespace std;

typedef long long ll;
typedef pairint, int> PII;

#define Time (double)clock() / CLOCKS_PER_SEC

#define sd(a) scanf("%d", &a)
#define sdd(a, b) scanf("%d%d", &a, &b)
#define slld(a) scanf("%lld", &a)
#define slldd(a, b) scanf("%lld%lld", &a, &b)

const int N = 1e5 + 20;
const int M = 1e6 + 20;
const int mod = 1e9 + 7;

int n;
int a[N];
int cnt[M], ans[M];

void solve()
{
    sd(n);
    int num;
    for(int i = 0; i ){
        sd(a[i]);
        cnt[a[i]] ++;
        num = max(num, a[i]);
    }
    for(int i = 1; i ){
        for(int j = i; j  i){
            ans[j] += cnt[i];
        }
    }

    for(int i = 0; i ){
        printf("%d\n", ans[a[i]] - 1);
    }
}

int main()
{
#ifdef ONLINE_JUDGE
#else
    freopen("/home/jungu/code/in.txt", "r", stdin);
    // freopen("/home/jungu/code/out.txt", "w", stdout);
    // freopen("/home/jungu/code/out.txt","w",stdout);
#endif
    // ios::sync_with_stdio(false);
    cin.tie(0), cout.tie(0);

    int T = 1;
    // sd(T);
    while(T --){
        solve();
    }

    return 0;
}

 

Acwing 1291.轻拍牛头

标签:const   lse   scanf   暴力   out   define   stream   其他   max   

原文地址:https://www.cnblogs.com/jungu/p/13383134.html


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