https://code.google.com/codejam/contest/11254486/dashboard

CodeJam: Getting_the_Digits.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define S_LEN       2048
#define DIGIT_LEN   10

struct {
    char c;
    char * word;
    size_t digit;
} Rule[10] = {
    // ROUND ONE
    { 'Z', "ZERO",  0 },
    { 'W', "TWO",   2 },
    { 'U', "FOUR",  4 },
    { 'X', "SIX",   6 },
    { 'G', "EIGHT", 8 },

    // ROUND TWO
    { 'H', "THREE", 3 },
    { 'F', "FIVE",  5 },
    { 'S', "SEVEN", 7 },

    // ROUND TREE
    { 'O', "ONE",  1 },
    { 'I', "NINE", 9 }
};

void solution (const char * input, const size_t inputLen, int digitCounter[DIGIT_LEN]);

int main (int argc, char const * argv[]) {
    struct {
        FILE * in;
        FILE * out;
    } stream = {
        // .in  = stdin,
        // .out = stdout,
        .in  = fopen("A-large-practice.in", "r"),
        .out = fopen("A-large-practice.out", "w"),
    };

    int T;
    fscanf(stream.in, "%d", &T);

    for (int caseIndex = 1; caseIndex <= T; caseIndex++) {
        // get S
        char S[S_LEN] = {};
        fscanf(stream.in, "%s", S);

        // get result
        int counter[DIGIT_LEN] = {};
        solution(S, strlen(S), counter);

        // show result
        fprintf(stream.out, "Case #%d: ", caseIndex + 1);
        for (int digit = 0; digit < DIGIT_LEN; digit++) {
            for (int i = 1; i <= counter[digit]; i++) {
                fprintf(stream.out, "%d", digit);
            }
        }
        fprintf(stream.out, "\n");
    }

    return 0;
}

// O(n)
void solution (const char * input, size_t inputLen, int digitCounter[DIGIT_LEN]) {
    // reset (0-9)
    memset(digitCounter, 0, DIGIT_LEN);

    // the number of each character (A-Z)
    int characterCounter[26] = {};
    for (size_t i = 0; i < inputLen; i++) {
        size_t index = input[i] - 65;
        characterCounter[index]++;
    }

    for (size_t i = 0; inputLen > 0 && i < DIGIT_LEN; i++) {
        const char c = Rule[i].c;
        const int num = characterCounter[c - 65];    // number of word
        if (num == 0) {
            continue;
        }

        // result
        digitCounter[Rule[i].digit] = num;

        // reduce number of character
        const char * word = Rule[i].word;
        const size_t len = strlen(word);

        for (int j = 0; j < len; j++) {
            characterCounter[word[j] - 65] -= num;
        }

        // reduce len
        inputLen -= num * len;
    }

    // check: length should be zero
    if (inputLen != 0) {
        puts("\n\n");
        puts("Error!!!");
        printf("%s\n", input);
        printf("len = %zu\n", inputLen);
        for (int i = 0; i < DIGIT_LEN; i++) {
            printf("%d ", digitCounter[i]);
        }
        puts("\n\n");
    }
}