5 1 2 3 4 5
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#include<stdio.h>
int main()
{
int n,i,j,k,kk,a[100050];
while(scanf("%d",&n)!=EOF)
{
for(i=1; i<=n; i++)
scanf("%d",&a[i]);
long long suma=0;
for(i=1; i<=n; i++)
{
for(j=i; j<=n; j++)
{
for(k=i; k<=j; k++)//相当于i
{
int flag=0;
for(kk=i; kk <= j ; kk++)//相当于j
{
if(a[k]%a[kk] == 0 && k!=kk)
{
flag=1;
break;
}
}
if(flag!=1)
{
suma++;
suma%=100000007;
}
}
printf("%d %d=%d %d=%d\n",i,j,a[i],a[j],suma);
}
}
printf("%I64d\n",suma);
}
}
脑洞大开:换个思路是不是题意求的是找那些区间能满足第ai个值存在呢?#include <iostream>
#include <stdio.h>
#include <string.h>
#include <algorithm>
#include <math.h>
using namespace std;
const int M = 10e5 + 5;
const long mod = 1e9+7;
int vis[M],a[M],l[M],r[M];
int main()
{
int n;
while(~scanf("%d",&n))
{
memset(l,0,sizeof(l));
memset(r,0,sizeof(r));
memset(vis,0,sizeof(vis));
for(int i = 1;i <= n; ++i)
{
scanf("%d",&a[i]);
r[i] = n+1;
for(int j = a[i];j <= 10000; j+=a[i]) //找到离他近期的因子
{
if(vis[j])
{
r[vis[j]] = i;
vis[j] = 0;
}
}
vis[a[i]] = i;
}
memset(vis,0,sizeof(vis));
for(int i = n;i >= 1; --i)
{
for(int j = a[i];j <= 10000; j+=a[i])
{
if(vis[j])
{
l[vis[j]] = i;
vis[j] = 0;
}
}
vis[a[i]] = i;
}
long long ans = 0;
for(int i = 1;i <= n; ++i)
{
ans = ((ans + (long long)(r[i]-i)*(long long)(i-l[i])%mod)%mod);
}
printf("%I64d\n",ans);
}
}
Hdu 5288 OO’s Sequence 2015多小联赛A题
原文:http://www.cnblogs.com/wzjhoutai/p/7232012.html