Added C solutions of Arrays & Strings

Ch 01. Arrays and Strings/1.1_isUnique.c

@@ -0,0 +1,32 @@
+#include <stdio.h>
+#include <string.h>
+int isUnique(char*, int);
+
+int main()
+{
+    char s[1000];
+    printf("Input: ");
+    scanf("%[^\n]", s);
+    if(isUnique(s, strlen(s)) == 1)
+        printf("%s is unique.\n", s);
+    else
+        printf("%s is not unique.\n", s);
+    return 0;
+}
+
+int isUnique(char* s, int len)
+{
+    int ascii[128], i;
+    if(len > 128)
+        return 0;
+    for(i = 0; i < 128; i++)
+        ascii[i] = 0;
+    for(i = 0; i < len; i++)
+    {
+        if(ascii[s[i]] != 0)
+            return 0;
+        else
+            ascii[s[i]]++;
+    }
+    return 1;
+}

Ch 01. Arrays and Strings/1.2_checkPermutation.c

@@ -0,0 +1,38 @@
+#include<stdio.h>
+#include<string.h>
+int checkPermutation(char*, char*, int, int);
+
+int main()
+{
+    char s1[1000], s2[1000];
+    printf("String 1: ");
+    scanf("%s", s1);
+    printf("String 2: ");
+    scanf("%s", s2);
+    if(checkPermutation(s1, s2, strlen(s1), strlen(s2)) == 1)
+        printf("YES\n");
+    else
+        printf("NO\n");
+    return 0;
+}
+
+int checkPermutation(char* s1, char* s2, int len1, int len2)
+{
+    int ascii[128], i;
+    if(len1 != len2)
+        return 0;
+    else
+    {
+        for(i = 0; i < 128; i++)
+            ascii[i] = 0;
+        for(i = 0; i < len1; i++)
+            ascii[s1[i]]++;
+        for(i = 0; i < len2; i++)
+        {
+            ascii[s2[i]]--;
+            if(ascii[s2[i]] < 0)
+                return 0;
+        }
+    }
+    return 1;
+}

Ch 01. Arrays and Strings/1.3_URLify.c

@@ -0,0 +1,38 @@
+#include <stdio.h>
+#include <string.h>
+void URLify(char*, int);
+
+int main()
+{
+    char s[1000];
+    printf("Input: ");
+    scanf("%[^\n]", s);
+    printf("URLify(\"%s\") = ", s);
+    URLify(s, strlen(s));
+    printf("%s\n", s);
+    return 0;
+}
+
+void URLify(char* s, int len)
+{
+    int i, j = len - 1;
+    while(s[j] == ' ' && j>=0)
+        j--;
+    if(j >= 0)
+    {
+        i = len - 1;
+        for(; j >= 0; j--)
+        {
+            if(s[j] == ' ')
+            {
+                s[i--] = '0';
+                s[i--] = '2';
+                s[i--] = '%';
+            }
+            else
+                s[i--] = s[j];
+        }
+        for(j = 0; j < len; j++)
+            s[j] = s[j+i+1];
+    }
+}

Ch 01. Arrays and Strings/1.4_isPermutationOfPalindrome.c

@@ -0,0 +1,36 @@
+#include <stdio.h>
+#include <string.h>
+int isPermutationOfPalindrome(char*, int);
+
+int main()
+{
+    char s[1000];
+    printf("Input: ");
+    scanf("%[^\n]", s);
+    if(isPermutationOfPalindrome(s, strlen(s)) == 1)
+        printf("YES\n");
+    else
+        printf("NO\n");
+    return 0;
+}
+
+int isPermutationOfPalindrome(char* s, int len)
+{
+    char ascii[128];
+    int i, odd = 0;
+    for(i = 0; i < 128; i++)
+        ascii[i] = 0;
+    for(i = 0; i < len; i++)
+        ascii[s[i]]++;
+    for(i = 0; i < 128; i++)
+    {
+        if(i >= 65 && i <= 90 || i >= 97 && i <=122)
+        {
+            if(ascii[i]%2 != 0)
+                odd++;
+            if(odd > 1)
+                return 0;
+        }
+    }
+    return 1;
+}

Ch 01. Arrays and Strings/1.5_oneAway.c

@@ -0,0 +1,93 @@
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+void oneAway(char*, char*, int, int);
+
+int main()
+{
+    char s1[1000], s2[1000];
+    printf("String 1: ");
+    scanf("%s", s1);
+    printf("String 2: ");
+    scanf("%s", s2);
+    oneAway(s1, s2, strlen(s1), strlen(s2));
+    return 0;
+}
+
+void oneAway(char* s1, char* s2, int len_a, int len_b)
+{
+    int matches, i, flag1 = 0, flag2 = 0, len = len_a;
+    if(len_a != len_b && len_a + 1 != len_b && len_a != len_b + 1)
+    {
+        printf("More than an edit away.\n");
+        return;
+    }
+    if(len_a > len_b)
+        len = len_b;
+    for(i = 0; i < len; i++)
+    {
+        if(s1[i + flag1] == s2[i + flag2])
+            matches++;
+        else
+        {
+            if(len_a == len_b)
+            {
+                if(flag1 == 0 && flag2 == 0)
+                {
+                    flag1++;
+                    flag2++;
+                }
+                else
+                {
+                    printf("More than an edit away.\n");
+                    return;
+                }
+            }
+            else if(len_a == len_b + 1)
+            {
+                if(flag1 == 0)
+                {
+                    flag1++;
+                    i--;
+                }
+                else
+                {
+                    printf("More than an edit away.\n");
+                    return;
+                }
+            }
+            else if(len_a + 1 == len_b)
+            {
+                if(flag2 == 0)
+                {
+                    flag2++;
+                    i--;
+                }
+                else
+                {
+                    printf("More than an edit away.\n");
+                    return;
+                }
+            }
+            else
+            {
+                printf("More than an edit away.\n");
+                return;
+            }
+        }
+    }
+
+    if(flag1 == 0 && flag2 == 0 && len_a == len_b)
+    {
+        printf("0 edits away.\n");
+        return;
+    }
+    else if((flag1 == 0 && flag2 == 0 && (len_a == len_b + 1 || len_a + 1 == len_b)) || (flag1 == 0 && flag2 == 1 && len_a + 1 == len_b) || (flag1 == 1 && flag2 == 0 && len_a == len_b + 1))
+    {
+        printf("1 edit away.\n");
+        return;
+    }
+    else
+        printf("More than an edit away.\n");
+    return;
+}

Ch 01. Arrays and Strings/1.6_compress.c

@@ -0,0 +1,47 @@
+#include <stdio.h>
+#include <string.h>
+char* compress(char* s, int len);
+
+int main()
+{
+    char s[1000];
+    printf("Input: ");
+    scanf("%s", s);
+    printf("On compression: %s\n", compress(s, strlen(s)));
+    return 0;
+}
+
+char* compress(char* s, int len)
+{
+    char result[len+1], temp;
+    int i, j = len - 1, count;
+    for(i = len - 1; i >= 0;)
+    {
+        count = 0;
+        temp = s[i];
+        while(s[i] == temp && i >= 0)
+        {
+            count++;
+            i--;
+        }
+        while(count > 0)
+        {
+            result[j--] = (count%10) + 48;
+            count /= 10;
+            if(j == -1)
+                return s;
+        }
+        result[j--] = temp;
+        if(j == -1 && i != 0)
+            return s;
+    }
+    i = 0;
+    while(i+j+1 <= len)
+    {
+        result[i] = result[i+j+1];
+        i++;
+    }
+    result[len] = '\0';
+    s = result;
+    return s;
+}

Ch 01. Arrays and Strings/1.7_rotate.c

@@ -0,0 +1,55 @@
+#include <stdio.h>
+#include <stdlib.h>
+void rotate(int**, int, int);
+void rotateEdge(int**, int, int);
+
+int main()
+{
+    int** img, N, i, j;
+    printf("N: ");
+    scanf("%d", &N);
+    img = (int**)malloc(N*sizeof(int*));
+    for(i = 0; i < N; i++)
+        img[i] = (int*)malloc(N*sizeof(int));
+    printf("Enter the image matrix:\n");
+    for(i = 0; i < N; i++)
+        for(j = 0; j < N; j++)
+            scanf("%d", &img[i][j]);
+    rotate(img, 0, N-1);
+    printf("\nOn rotation:\n");
+    for(i = 0; i < N; i++)
+    {
+        for(j = 0; j < N; j++)
+            printf("%d\t", img[i][j]);
+        printf("\n");
+    }
+    return 0;
+}
+
+// a: first element index in submatrix of top row, b: last element index in submatrix of top row
+void rotate(int** img, int a, int b)
+{
+    if(a < b)
+    {
+        rotateEdge(img, a, b);
+        rotate(img, a+1, b-1);
+    }
+}
+
+void rotateEdge(int** img, int a, int b)
+{
+    int i, temp;
+    for(i = a; i < b; i++)
+    {
+        // store right in temp
+        // up to right
+        // left to up
+        // bottom to left
+        // temp to bottom
+        temp = img[i][b];
+        img[i][b] = img[a][i];
+        img[a][i] = img[b-(i-a)][a];
+        img[b-(i-a)][a] = img[b][b-(i-a)];
+        img[b][b-(i-a)] = temp;
+    }
+}