init commit

3sem/cnts/contest1/02.c

@@ -0,0 +1,53 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+enum
+{
+    NUM_OF_DIGITS = '9' - '0' + 1,
+    NUM_OF_LETTERS = 'z' - 'a' + 1,
+    BIT_MASK_1 = 0b111011,
+    BIT_MASK_2 = 0b001000,
+    MAX_NUM = 64,
+};
+
+int
+main(void)
+{
+    int c;
+
+    while ((c = getchar()) != EOF) {
+        int code = 0;
+
+        if (c <= '9' && c >= '0') {
+            code = c - '0' + 1;
+        } else if (c <= 'z' && c >= 'a') {
+            code = c - 'a' + NUM_OF_DIGITS + 1;
+        } else if (c <= 'Z' && c >= 'A') {
+            code = c - 'A' + NUM_OF_DIGITS + NUM_OF_LETTERS + 1;
+        }
+
+        if (code == 0) {
+            continue;
+        }
+
+        code = code & BIT_MASK_1;
+        code ^= BIT_MASK_2;
+
+        int res = 0;
+        if (code <= NUM_OF_DIGITS && code >= 1) {
+            res = code - 1 + '0';
+        } else if (code <= NUM_OF_DIGITS + NUM_OF_LETTERS && code >= NUM_OF_DIGITS + 1) {
+            res = code + 'a' - NUM_OF_DIGITS - 1;
+        } else if (code <= NUM_OF_DIGITS + NUM_OF_LETTERS * 2 && code >= NUM_OF_DIGITS + NUM_OF_LETTERS + 1) {
+            res = code + 'A' - NUM_OF_DIGITS - NUM_OF_LETTERS - 1;
+        } else if (code == 0) {
+            res = '@';
+        } else if (code == MAX_NUM - 1) {
+            res = '#';
+        }
+
+        putchar(res);
+    }
+
+    return 0;
+}

3sem/cnts/contest1/03.c

@@ -0,0 +1,80 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+enum
+{
+    MAX_N = 2000
+};
+
+int
+is_prime(int num)
+{
+    if (num <= 1) {
+        return 0;
+    }
+    if (num <= 3) {
+        return 1;
+    }
+    if (num % 2 == 0 || num % 3 == 0) {
+        return 0;
+    }
+    for (int i = 5; i * i <= num; i += 6) {
+        if (num % i == 0 || num % (i + 2) == 0) {
+            return 0;
+        }
+    }
+    return 1;
+}
+
+int
+main(void)
+{
+    int n;
+    if (scanf("%d", &n) != 1) {
+        fprintf(stderr, "Error reading input\n");
+        return 1;
+    }
+
+    if (n >= MAX_N || !is_prime(n)) {
+        return 1;
+    }
+
+    // двумерный под хранение результата. Не может быть одномерным, т.к. заполняются столбцы по порядку
+    int **mas = (int **) malloc(n * sizeof(mas));
+    if (mas == NULL) {
+        return 1;
+    }
+
+    for (int i = 0; i < n; i++) {
+        mas[i] = (int *) malloc(n * sizeof(*mas));
+
+        if (mas[i] == NULL) {
+            for (int j = 0; j < i; j++) {
+                free(mas[j]);
+            }
+
+            free(mas);
+            return 1;
+        }
+    }
+
+    for (int i = 1; i < n; i++) {
+        for (int a = 0; a < n; a++) {
+            mas[i][(a * i) % n] = a;
+        }
+    }
+
+    for (int j = 0; j < n; j++) {
+        for (int i = 1; i < n; i++) {
+            printf("%d ", mas[i][j]);
+        }
+        printf("\n");
+    }
+
+    for (int i = 0; i < n; i++) {
+        free(mas[i]);
+    }
+    free(mas);
+
+    return 0;
+}

3sem/cnts/contest1/05.c

@@ -0,0 +1,78 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+void
+swap(int *a, int *b)
+{
+    int temp = *a;
+    *a = *b;
+    *b = temp;
+
+    return;
+}
+
+int
+next_permutation(int *arr, int n)
+{
+    int i = n - 2;
+
+    while (i >= 0 && arr[i] >= arr[i + 1]) {
+        i--;
+    }
+
+    if (i < 0) {
+        return 0;
+    }
+
+    int j = n - 1;
+
+    while (arr[j] <= arr[i]) {
+        j--;
+    }
+
+    swap(&arr[i], &arr[j]);
+
+    int pt1 = i + 1, pt2 = n - 1;
+
+    while (pt1 < pt2) {
+        swap(&arr[pt1++], &arr[pt2--]);
+    }
+
+    return 1;
+}
+
+int
+main()
+{
+    int n;
+
+    if (scanf("%d", &n) != 1) {
+        fprintf(stderr, "Error reading input\n");
+        return 1;
+    }
+
+    if (n <= 0 || n >= 10) {
+        return 1;
+    }
+
+    int *arr = (int *) malloc(n * sizeof(*arr));
+    if (arr == NULL) {
+        return 1;
+    }
+
+    for (int i = 0; i < n; i++) {
+        arr[i] = i + 1;
+    }
+
+    do {
+        for (int i = 0; i < n; i++) {
+            printf("%d", arr[i]);
+        }
+
+        printf("\n");
+    } while (next_permutation(arr, n));
+
+    free(arr);
+
+    return 0;
+}

3sem/cnts/contest1/test.c

@@ -0,0 +1,51 @@
+#include <stdlib.h>
+#include <malloc.h>
+#include <stdio.h>
+
+int
+cmp(const void *a, const void *b)
+{
+    if (*(int *) a % 2 == 0) {
+        if (*(int *) b % 2 == 1) {
+            return -1;
+        }
+        if (*(int *) a > *(int *) b) {
+            return 1;
+        }
+        if (*(int *) a < *(int *) b) {
+            return -1;
+        }
+        return 0;
+    }
+    if (*(int *) b % 2 == 0) {
+        return 1;
+    }
+    if (*(int *) a > *(int *) b) {
+        return -1;
+    }
+    if (*(int *) a < *(int *) b) {
+        return 1;
+    }
+    return 0;
+}
+
+void
+sort_even_odd(size_t count, int *data)
+{
+    qsort(data, count, sizeof(int), cmp);
+}
+
+int
+main()
+{
+    int a[] = {4, 2, 5, 3, 1, 0, -4, -2, -68, 23, 3};
+    sort_even_odd(sizeof(a) / sizeof(a[0]), a);
+
+    for (int i = 0; i < sizeof(a) / sizeof(a[0]); i++) {
+        printf("%d ", a[i]);
+    }
+
+    printf("\n");
+
+    return 0;
+}