题目:http://codeforces.com/contest/270/problem/B
思路:找出最后一个不满足升序的数字
#include <iostream> using namespace std; int arr[100005]; int main() { int n; cin>>n; for (int i = 0; i < n; i++) { cin>>arr[i]; } int i; for ( i= n-2; i >= 0; i--) { if(arr[i]>arr[i+1]) break; } cout<<i+1; return 0; }