Completed problem 16! Implemented big number utils

Co-authored-by: sigonasr2 <sigonasr2@gmail.com>

archives/16/src/main.c

@@ -0,0 +1,27 @@
+#include <stdio.h>
+#include "utils.h"
+
+/*
+    215 = 32768 and the sum of its digits is 3 + 2 + 7 + 6 + 8 = 26.
+
+    What is the sum of the digits of the number 21000?
+
+
+    https://projecteuler.net/problem=16
+*/
+
+int main(int argc,char**argv) {
+    
+    int i=1;
+    struct String numb = {1,"2"};
+    while (i++<1000) {
+        numb = add(numb,numb);
+    }
+    //printf("%s",numb.str);
+    int sum=0;
+    for (int j=0;j<numb.length;j++) {
+        sum+=numb.str[j]-'0';
+    }
+    printf("The sum of the digits of %s is %d",numb.str,sum);
+    return 0;
+}

archives/16/src/utils.c

@@ -0,0 +1,40 @@
+#include "utils.h"
+#include <stdio.h>
+#include <stdlib.h>
+
+struct String add(struct String numb1, struct String numb2){
+    byte carryover=0;
+    int digitCount=0;
+    char*str = malloc(0);
+    if (numb1.length>=numb2.length) {
+        for (int offset=0;offset<numb1.length;offset++) {
+            str = realloc(str,++digitCount);
+            //printf("Digit count is now %d\n",digitCount);
+            if (numb2.length>offset) {
+                //printf("%c %c\n",numb1.str[numb1.length-offset-1],numb2.str[numb2.length-offset-1]);
+                int sum=((numb1.str[numb1.length-offset-1]-'0')+(numb2.str[numb2.length-offset-1]-'0'))+((carryover>0)?carryover--:0);
+                if (sum>=10) {
+                    carryover=1;
+                    sum-=10;
+                }
+                str[offset]=sum+'0';
+            } else {
+                str[offset]=numb1.str[numb1.length-offset-1];
+            }
+        }
+    } else {
+
+    }
+    if (carryover>0) {
+        str = realloc(str,++digitCount);
+        str[digitCount-1]='1';
+    }
+    for (int i=0;i<digitCount/2;i++) {
+        char c = str[i];
+        char c2 = str[digitCount-i-1];
+        str[digitCount-i-1]=c;
+        str[i]=c2;
+    }
+    struct String newStr = {digitCount,str};
+    return newStr;
+}

archives/16/src/utils.h

@@ -0,0 +1,9 @@
+#define true 1
+#define false 0
+#define boolean char
+#define byte char
+struct String{
+    int length;
+    char*str;
+};
+struct String add(struct String numb1, struct String numb2);

src/main.c

@@ -2,12 +2,26 @@
 #include "utils.h"
 
 /*
+    215 = 32768 and the sum of its digits is 3 + 2 + 7 + 6 + 8 = 26.
 
+    What is the sum of the digits of the number 21000?
 
-    https://projecteuler.net/problem=
+
+    https://projecteuler.net/problem=16
 */
 
 int main(int argc,char**argv) {
     
+    int i=1;
+    struct String numb = {1,"2"};
+    while (i++<1000) {
+        numb = add(numb,numb);
+    }
+    //printf("%s",numb.str);
+    int sum=0;
+    for (int j=0;j<numb.length;j++) {
+        sum+=numb.str[j]-'0';
+    }
+    printf("The sum of the digits of %s is %d",numb.str,sum);
     return 0;
 }

src/utils.c

@@ -0,0 +1,40 @@
+#include "utils.h"
+#include <stdio.h>
+#include <stdlib.h>
+
+struct String add(struct String numb1, struct String numb2){
+    byte carryover=0;
+    int digitCount=0;
+    char*str = malloc(0);
+    if (numb1.length>=numb2.length) {
+        for (int offset=0;offset<numb1.length;offset++) {
+            str = realloc(str,++digitCount);
+            //printf("Digit count is now %d\n",digitCount);
+            if (numb2.length>offset) {
+                //printf("%c %c\n",numb1.str[numb1.length-offset-1],numb2.str[numb2.length-offset-1]);
+                int sum=((numb1.str[numb1.length-offset-1]-'0')+(numb2.str[numb2.length-offset-1]-'0'))+((carryover>0)?carryover--:0);
+                if (sum>=10) {
+                    carryover=1;
+                    sum-=10;
+                }
+                str[offset]=sum+'0';
+            } else {
+                str[offset]=numb1.str[numb1.length-offset-1];
+            }
+        }
+    } else {
+
+    }
+    if (carryover>0) {
+        str = realloc(str,++digitCount);
+        str[digitCount-1]='1';
+    }
+    for (int i=0;i<digitCount/2;i++) {
+        char c = str[i];
+        char c2 = str[digitCount-i-1];
+        str[digitCount-i-1]=c;
+        str[i]=c2;
+    }
+    struct String newStr = {digitCount,str};
+    return newStr;
+}

src/utils.h

@@ -1,7 +1,9 @@
 #define true 1
 #define false 0
 #define boolean char
+#define byte char
 struct String{
     int length;
     char*str;
 };
+struct String add(struct String numb1, struct String numb2);