Merkkijono

input/code.cpp: In function 'int main()':
input/code.cpp:6:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d", &numPhases);
     ~~~~~^~~~~~~~~~~~~~~~~~

#include <stdio.h>

int main() {
    int numPhases, arrayLength, strLength, tmpLength;
    char *str, *tmp;
    scanf("%d", &numPhases);

    if(numPhases < 2) {
        printf("a");
        return 0;
    }
    
    arrayLength = 2;
    for(int i = 1; i < numPhases; i++){
        arrayLength *= 2;
    }
    arrayLength -= 1;

    str = new char[arrayLength];
    tmp = new char[arrayLength];
    tmp[0] = 'a';
    strLength = 1;
    tmpLength = 1;

    for(int i = 1; i < numPhases; i++) {
        // Place the next character in front of every character in str
        for(int j = 0; j < tmpLength; j++){
            str[2 * j] = 'a' + i;
            str[2 * j + 1] = tmp[j];
            strLength++;
        }
        // Place the next character in the alphabet into the end
        str[strLength] = 'a' + i;
        strLength++;
        // Copy str to tmp
        for(int j = 0; j < strLength; j++) tmp[j] = str[j];
        tmpLength = strLength;
    }
    printf("%s", str);
    return 0;
}

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED

Test 3

Verdict: ACCEPTED

Test 4

Verdict: ACCEPTED

Test 5

Verdict: ACCEPTED

Test 6

Verdict: ACCEPTED

Test 7

Verdict: ACCEPTED

Test 8

Verdict: ACCEPTED

Test 9

Verdict: ACCEPTED

Test 10

Verdict: ACCEPTED

Test 11

Verdict: ACCEPTED

Test 12

Verdict: ACCEPTED

Test 13

Verdict: ACCEPTED

Test 14

Verdict: ACCEPTED

Test 15

Verdict: ACCEPTED

Test 16

Verdict: ACCEPTED