(Jizhong) 2192. Sum

(File IO): input: sum.in output: sum.out
time limit: 1000 ms space limitations: 65536 KB specific restrictions
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Title description
given $n$ number $a1..an$ , the absolute value of the minimum sum of two numbers
i.e. seek $| ai + aj |$ ( $i$ is not equal to $j$ ) minimum

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Enter
a number of the first row $n$
the next line $n$ number $a1..an$

Output
line a number $years$ minimum value, the absolute value of the sum of two numbers

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Sample input
. 5
-2. 6. 7. 7 -8

Sample output
1

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Data range limit
• For $40$ % of the data, $n <= 10^3，-10^6 <= ai <= 10^6$ .
• For $80$ % of the data, n-$ <= 10^{. 5, -10}. 6 <AI = <= 10. 6 ^.
• For $100$ % of the data, $n <= 10^6，-10^6 <= ai <= 10^6$。

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Solving ideas
first with absolute value of each number sequence as a row key, and then every two adjacent numbers together and seek a minimum.

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Code

#include<iostream>
#include<cstring>
#include<string>
#include<cstdio>
#include<algorithm>
#include<iomanip>
#include<cmath>
using namespace std;
int n,a[1000000],ans;
bool cmp(int x,int y)
{
	return abs(x)<abs(y);
}
int main()
{
	freopen("sum.in","r",stdin);
    freopen("sum.out","w",stdout);
    scanf("%d",&n);
    for(int i=1;i<=n;i++)
        scanf("%d",&a[i]);
    sort(a+1,a+n+1,cmp);
    ans=2147483647;
    for(int i=2;i<=n;i++)
    {
    	if(abs(a[i]+a[i-1])<ans)
    	ans=abs(a[i]+a[i-1]);
	}
    printf("%d",ans);
}