uva10008.c

uva10008.c

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

struct Node_
{
    char c;
    int cnt;
};

typedef struct Node_ Node;

int compare_node(const void * a, const void * b)
{
    Node* na = (Node*) a;
    Node* nb = (Node*) b;
    if (na->cnt > nb->cnt)
        return -1;
    if (na->cnt < nb->cnt)
        return +1;
    if (na->c < nb->c)
        return -1;
    if (na->c > nb->c)
        return +1;
    return 0;
}

int main() {
    int N;
    scanf("%d\n", &N);
    
    Node data[26];
    int i;
    for (i=0; i<26; i++) {
        data[i].c = (char) (i + 'A');
        data[i].cnt = 0;
    }
    
    while (N--) {
        char inp[1024];
        
        fgets(inp, 1024, stdin);
        int len = strlen(inp);
        if (inp[len-1] == '\n') {
            inp[len-1] = '\0';
            len--;
        }
        
        for (i=0; i<len; i++)
            if (islower(inp[i]))
                inp[i] = inp[i] - 'a' + 'A';
        
        for (i=0; i<len; i++)
            if (isalpha(inp[i]))
                data[(int) (inp[i] - 'A')].cnt++;

    }
    
    qsort(data, 26, sizeof(Node), compare_node);
    
    for (i=0; i<26; i++) 
        if (data[i].cnt != 0)
            printf("%c %d\n", data[i].c, data[i].cnt);
    
    return 0;
}