Codeforces 451 B. Sort the Array

题目链接：http://codeforces.com/contest/451/problem/B

#include <iostream>
#include <cstdio>
#include <cmath>
#include <algorithm>
using namespace std;
typedef long long LL;
const int maxn=1e5+5;
int a[maxn];
int b[maxn];
int main()
{
    int m,j,k;
    while(cin>>m)
    {
        j=k=0;
        for(int i=0; i<m; i++)
          cin>>a[i],b[i]=a[i];
        sort(b,b+m);
        for(int i=0; i<m; i++)
            if(b[i]!=a[i])
            {
                j=i;
                break;
            }
        for(int i=m-1;  i>=0; i--)
            if(b[i]!=a[i])
            {
                k=i;
                break;
            }
        int sum=0;
        for(int i=j; i<=k; i++)
        {
            if(a[i]==b[k-i+j])
            sum++;
        }
        //cout<<j<<"  "<<k<<"   "<<sum<<endl;
        if(sum == (k-j+1))
            puts("yes"),cout<<j+1<<" "<<k+1<<endl;
        else
            puts("no");
    }
    return 0;
}