Add implementation for finding Modified Kaprekar Numbers

This commit introduces a new program to identify and print Modified Kaprekar Numbers within a given range. It computes squares, splits them, and verifies the Kaprekar condition. Handles input parsing, output formatting, and edge cases like invalid ranges.

Author: holman57

ModifiedKaprekarNumbers.c

@@ -0,0 +1,160 @@
+#include <assert.h>
+#include <ctype.h>
+#include <limits.h>
+#include <math.h>
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+char* readline();
+char* ltrim(char*);
+char* rtrim(char*);
+
+int parse_int(char*);
+
+void kaprekarNumbers(int p, int q) {
+    int found = 0; // To track if we find any Kaprekar number
+
+    for (int i = p; i <= q; i++) {
+        long square = (long)i * i; // Compute the square of the number
+        char square_str[20]; // To hold the square as string
+        sprintf(square_str, "%ld", square); // Convert square to string
+        int len = strlen(square_str); // Total number of digits in the square
+
+        char left_part[20] = {0}, right_part[20] = {0};
+        int split_pos = len - (int)log10(i) - 1; // Calculate split position
+
+        // Split the string
+        strncpy(left_part, square_str, split_pos); // Left part
+        strcpy(right_part, square_str + split_pos); // Right part
+
+        // Convert parts to integers
+        long left_num = (left_part[0] != '\0') ? atol(left_part) : 0;
+        long right_num = atol(right_part);
+
+        // Sum the parts and check if it equals the original number
+        if ((left_num + right_num) == i) {
+            printf("%d ", i);
+            found = 1;
+        }
+    }
+
+    if (!found) {
+        printf("INVALID RANGE");
+    }
+
+    printf("\n"); // End the output with a newline
+}
+
+int main()
+{
+    int p = parse_int(ltrim(rtrim(readline())));
+
+    int q = parse_int(ltrim(rtrim(readline())));
+
+    kaprekarNumbers(p, q);
+
+    return 0;
+}
+
+char* readline() {
+    size_t alloc_length = 1024;
+    size_t data_length = 0;
+
+    char* data = malloc(alloc_length);
+
+    while (true) {
+        char* cursor = data + data_length;
+        char* line = fgets(cursor, alloc_length - data_length, stdin);
+
+        if (!line) {
+            break;
+        }
+
+        data_length += strlen(cursor);
+
+        if (data_length < alloc_length - 1 || data[data_length - 1] == '\n') {
+            break;
+        }
+
+        alloc_length <<= 1;
+
+        data = realloc(data, alloc_length);
+
+        if (!data) {
+            data = '\0';
+
+            break;
+        }
+    }
+
+    if (data[data_length - 1] == '\n') {
+        data[data_length - 1] = '\0';
+
+        data = realloc(data, data_length);
+
+        if (!data) {
+            data = '\0';
+        }
+    } else {
+        data = realloc(data, data_length + 1);
+
+        if (!data) {
+            data = '\0';
+        } else {
+            data[data_length] = '\0';
+        }
+    }
+
+    return data;
+}
+
+char* ltrim(char* str) {
+    if (!str) {
+        return '\0';
+    }
+
+    if (!*str) {
+        return str;
+    }
+
+    while (*str != '\0' && isspace(*str)) {
+        str++;
+    }
+
+    return str;
+}
+
+char* rtrim(char* str) {
+    if (!str) {
+        return '\0';
+    }
+
+    if (!*str) {
+        return str;
+    }
+
+    char* end = str + strlen(str) - 1;
+
+    while (end >= str && isspace(*end)) {
+        end--;
+    }
+
+    *(end + 1) = '\0';
+
+    return str;
+}
+
+int parse_int(char* str) {
+    char* endptr;
+    int value = strtol(str, &endptr, 10);
+
+    if (endptr == str || *endptr != '\0') {
+        exit(EXIT_FAILURE);
+    }
+
+    return value;
+}