initial

Makefile

@@ -0,0 +1,4 @@
+GCC = gcc -O2
+
+default: main.c
+	$(GCC) main.c -o anagram

main.c

@@ -0,0 +1,160 @@
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <ctype.h>
+
+// for string qsort
+int compar(const void * l1, const void *l2) {
+    return *(char *)l1 > *(char*)l2;
+}
+
+#define LINELENGTH 200
+
+void make_lowercase(char *word) {
+    int j = 0;
+    while (word[j] != '\0') {
+        if (isupper(word[j])) {
+            word[j] = tolower(word[j]);
+        }
+        j++;
+    }
+}
+
+int *count_char(char *word) {
+    make_lowercase(word);
+    int* counts = calloc(27, sizeof(int));
+
+    int j = 0;
+    while (word[j] != '\0') {
+        if (word[j] > 'z' || word[j] < 'a') {
+            free(counts);
+            return 0;
+        }
+        counts[word[j] - 'a'] += 1;
+        j++;
+    }
+    return counts;
+}
+
+int get_minimum_match(char *word, int added) {
+    FILE *wfile = fopen("/usr/share/dict/words", "r");
+    char line[LINELENGTH];
+    int err;
+    int len = strlen(word);
+    int *min_letter_counts = count_char(word);
+    if (!min_letter_counts) {
+        fclose(wfile);
+        return 1;
+    }
+
+    do {
+        err = fscanf(wfile, "%s\n", line);
+        if (err == EOF) {
+            break;
+        }
+
+        int line_len = strlen(line);
+        if (line_len < len || line_len > (len + added)) {
+            continue;
+        }
+
+        int* word_counts = count_char(line);
+        if (!word_counts) {
+            continue;
+        }
+
+        int match = 1;
+
+        for (int i = 0; i < 26; i++) {
+            if (min_letter_counts[i] > word_counts[i]) {
+                match = 0;
+            }
+        }
+
+        if (match) {
+            printf("%s +", line);
+            for (int i = 0; i < 26; i++) {
+                int diff = word_counts[i] - min_letter_counts[i];
+                if (diff > 0) {
+                    printf(" %d%c", diff, i + 'a');
+                }
+            }
+            printf("\n");
+        }
+
+    } while (err != EOF);
+
+    free(min_letter_counts);
+    fclose(wfile);
+    return 0;
+}
+
+int get_exact_anag(char *word) {
+    FILE *wfile = fopen("/usr/share/dict/words", "r");
+    make_lowercase(word);
+
+    char line[LINELENGTH];
+    int err;
+    int len = strlen(word);
+    // sort line
+    qsort(word, len, sizeof(char), compar);
+
+    do {
+        err = fscanf(wfile, "%s\n", line);
+        if (err == EOF) {
+            break;
+        }
+        if (strlen(line) != len) {
+            continue;
+        }
+        make_lowercase(line);
+
+        char nline[LINELENGTH];
+        memcpy(nline, line, (sizeof(char) * LINELENGTH));
+
+        // sort line
+        qsort(line, len, sizeof(char), compar);
+
+        if (!strcmp(line, word)) {
+            printf("%s\n", nline);
+        }
+
+    } while (err != EOF);
+
+    fclose(wfile);
+
+    return 0;
+}
+
+int main (int argc, char **argv) {
+    
+    char word[LINELENGTH];
+
+    if (argc <= 2) {
+        printf("cmd min <word> numdiff\ncmd exact <word>\n");
+        return 1;
+    }
+
+    if (argv[1][0] == 'e') {
+        if (argc != 3) {
+            fprintf(stderr, "Wrong args.\n");
+            return 1;
+        }
+        strcpy(word, argv[2]);
+        get_exact_anag(word);
+    } else if (argv[1][0] == 'm') {
+        if (argc != 4) {
+            fprintf(stderr, "Wrong args.\n");
+            return 1;
+        }
+        int num = atoi(argv[2]);
+        strcpy(word, argv[3]);
+        if (num == 0) {
+            get_exact_anag(word);
+        } else {
+            get_minimum_match(word, num);
+        }
+    } else {
+        printf("cmd min <word> numdiff\ncmd exact <word>\n");
+    }
+}