histogram

#include <stdio.h>
int main(void) {
    int freq[6] = {0};
    int n;
    while (scanf("%d", &n) == 1) {
        if (n < 0 || 100 < n) {
            continue;
        }
        ++freq[n / 20];
    }
    freq[4] += freq[5]; // for 100
    // 12345678901234567890123456789012345678901234567890
    // 00-000| * * * * 5 * * * *10 * * * *15 * * * *20
    printf("%17d%10d%10d%10d\n", 5, 10, 15, 20);
    for (int i = 0; i < 5; ++i) {
        printf("%2d-%3d|", i * 20, ((i != 4) ? (i + 1) * 20 - 1 : 100));
        for (int j = 0; j < freq[i]; ++j) {
            printf(" *");
        }
        puts("");
    }
}