Ositus

input/code.cpp: In function 'int main()':
input/code.cpp:33:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%s", str);
     ~~~~~^~~~~~~~~~~

#include <stdio.h>
#include <stdint.h>

uint64_t getNumCombinations(char *str, uint32_t size, uint32_t previousIndx) {
    if(previousIndx + 1 >= size) return 1;
    uint64_t count;
    uint32_t chrCount[26];
    uint8_t chrIndex;
    
    for(uint8_t i = 0; i < 26; i++) chrCount[i] = 0;
    count = 0;

    for(uint32_t i = previousIndx + 1; i < size; i++) {
        chrIndex = str[i - 1] - 'a';

        chrCount[chrIndex]++;
        if(chrCount[chrIndex] > 1) return count;

        count += getNumCombinations(str, size, i) % 1000000007;
        count %= 1000000007;
    }
    if(chrCount[str[size - 1] - 'a'] == 0) count++;
    return count % 1000000007;
}

int main() {
    char str[1000001];
    uint32_t strLength, i;
    uint64_t combinationCount;
    
    for(i = 0; i < 1000001; i++) str[i] = '\0';
    
    scanf("%s", str);
    for(i = 0; i < 1000000 && str[i] != '\0'; i++);
    strLength = i;

    combinationCount = getNumCombinations(str, strLength, 0);
    printf("%lu", combinationCount);
    return 0;
}

Test 1

Group: 1, 2, 3

Verdict: ACCEPTED

Test 2

Group: 1, 2, 3

Verdict: ACCEPTED

Test 3

Group: 1, 2, 3

Verdict: ACCEPTED

Test 4

Group: 1, 2, 3

Verdict: ACCEPTED

Test 5

Group: 2, 3

Verdict: TIME LIMIT EXCEEDED

Test 6

Group: 3

Verdict: TIME LIMIT EXCEEDED

Test 7

Group: 3

Verdict: TIME LIMIT EXCEEDED