Järjestys

input/code.cpp: In function 'int main()':
input/code.cpp:81:34: error: variable-sized object 'old_arr' may not be initialized
   int old_arr[lastnotdone+1] = {0};
                                  ^

#include <iostream>
#include <sstream>
#include <cstdlib>
#include <cstring>

using namespace std;

int main() {
	std::ostringstream turns_oss;

	unsigned int length;
	unsigned int turns_count = 0;
	
    cin >> length;    
    
    int array[length];
    
    for (unsigned int i=0; i<length-1; i++) {
    	char input[6];
    	cin.getline(input, 6, ' ');
    	array[i] = atoi(input);
    }
    char input[6];
    cin.getline(input, 6);
    array[length-1] = atoi(input);
    
    
    int lastnotdone(length); // This is same as:
    lastnotdone--;           // int lastnotdone = length-1
    
    
	int nextmax(0);
    
	while (lastnotdone > 0) {
	
		int max(0);
		int max_i(0);
		for (int i=0; i<=lastnotdone; i++) {
			if (array[i] > max) {
				max = array[i];
				max_i = i;
			}
			if (max == nextmax) {
				break;
			}
		}
		nextmax = max;
		nextmax--;
		
		
		if (max_i == lastnotdone) {
			lastnotdone--;
			continue;
		}
		
		
		/*int temp;
		
		if (max_i != 0) {
			for (int i=0; i<=max_i/2; i++) {
				temp = array[i];
				array[i] = array[max_i-i];
				array[max_i-i] = temp;
			}
			
		}
		
		for (int i=0; i<=lastnotdone/2; i++) {
			temp = array[i];
			array[i] = array[lastnotdone-i];
			array[lastnotdone-i] = temp;
		}*/
		
		
		/*cout << "bef. ";
		for (int i=0; i<length; i++) {
			cout << array[i] << " ";
		}
		cout << '\n';*/
		
		int old_arr[lastnotdone+1] = {0};
		
		/*for (int i=0; i<=lastnotdone; i++) {
			old_arr[i] = array[i];
		}*/
		
		for (int i=0; i<=lastnotdone; i++) {
			if (old_arr[i] == 0) {
				old_arr[i] = array[i];
			}
			
			if (i<max_i) {
				old_arr[i+max_i] = array[i+max_i];
				array[i+max_i] = old_arr[i];
			} else {
				old_arr[lastnotdone-i] = array[lastnotdone-i];
				array[lastnotdone-i] = old_arr[i];
			}
		}
		
		/*cout << "aft. ";
		for (int i=0; i<length; i++) {
			cout << array[i] << " ";
		}
		cout << '\n' << '\n';*/
		
		
		if (max_i != 0) {
			turns_oss << (max_i+1) << (lastnotdone+1) << " ";
			turns_count += 2;
		} else {
			turns_oss << (lastnotdone+1) << " ";
			turns_count++;
		}
		
		lastnotdone--;		
	}
	
	
	
	cout << turns_count << '\n';
	cout << turns_oss.str() << endl;
}