Sort the Array

来源:互联网 发布:java人机猜拳代码 编辑:程序博客网 时间:2024/05/22 10:50

Being a programmer, you like arrays a lot. For your birthday, your friends have given you an array a consisting of n distinct integers.

Unfortunately, the size of a is too small. You want a bigger array! Your friends agree to give you a bigger array, but only if you are able to answer the following question correctly: is it possible to sort the array a (in increasing order) by reversing exactly one segment of a? See definitions of segment and reversing in the notes.

Input

The first line of the input contains an integer n (1 ≤ n ≤ 105) — the size of array a.

The second line contains n distinct space-separated integers: a[1], a[2], ..., a[n](1 ≤ a[i] ≤ 109).

Output

Print "yes" or "no" (without quotes), depending on the answer.

If your answer is "yes", then also print two space-separated integers denoting start and end (start must not be greater than end) indices of the segment to be reversed. If there are multiple ways of selecting these indices, print any of them.

Example
Input
33 2 1
Output
yes1 3
Input
42 1 3 4
Output
yes1 2
Input
43 1 2 4
Output
no
Input
21 2
Output
yes1 1
Note

Sample 1. You can reverse the entire array to get [1, 2, 3], which is sorted.

Sample 3. No segment can be reversed such that the array will be sorted.

Definitions

A segment [l, r] of array a is the sequence a[l], a[l + 1], ..., a[r].

If you have an array a of size n and you reverse its segment [l, r], the array will become:

a[1], a[2], ..., a[l - 2], a[l - 1], a[r], a[r - 1], ..., a[l + 1], a[l], a[r + 1], a[r + 2], ..., a[n - 1], a[n].


用排好序的数组b与原数组a对比,记录下第一个不同的位置的下标i和最后一个不同的位置的下标j,以a[i++]==b[j--]来做对比,只要有一个不相等即为no

#include<bits/stdc++.h>#define MAX 100005using namespace std;int a[MAX];int b[MAX];int main(){    int n;    while(scanf("%d",&n)!=EOF)    {        int l=0,r=0;        for(int i=1;i<=n;i++)        {            scanf("%d",&a[i]);            b[i] = a[i];        }        sort(b+1,b+n+1);        for(int i=1;i<=n;i++)        {            if(a[i]!=b[i])            {                r= i;                if(l==0)                l=i;            }        }        if(l==0) l=1;        if(r==0) r=1;        int i,j;        for(i=l,j=r;i<r;i++,j--)        {            if(a[i]!=b[j])            {                printf("no\n");                return 0;            }        }        printf("yes\n");        printf("%d %d\n",l,r);    }    return 0;}

原创粉丝点击