20/07/12测试

Posted 2020-12-17 vanyun

T1

搜索

和以前做过一道关于排序的题有亿点点像，看到这么小的数据范围竟然脑抽没去想搜索....

T2

筛法

换个方向思考，我们考虑这个数是几个数的倍数

#include <bits/stdc++.h>
using namespace std;

const int maxn = 1000000+10;

int n, sum, a[maxn], tong[maxn], ans[maxn];

signed main(){
	scanf("%d", &n);
	for(int i = 1; i <= n; ++ i){
		scanf("%d", &a[i]);
		tong[a[i]] ++;
		sum = max(a[i], sum);
	}
	for(int i = 1; i <= sum; ++ i){
		if(!tong[i]) continue;
		for(int j = 1; j*i<= sum; ++ j){
			ans[i*j] += tong[i];
		}
	}
	for(int i = 1; i <= n; ++ i){
		printf("%d
", ans[a[i]]-1);
	}
	return 0;
}

T3

区间DP