Setup mult()

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

src/main.c

@@ -2,88 +2,23 @@
 #include "utils.h"
 
 /*
-    You are given the following information, but you may prefer to do some research for yourself.
+    n! means n × (n − 1) × ... × 3 × 2 × 1
 
-    1 Jan 1900 was a Monday.
+    For example, 10! = 10 × 9 × ... × 3 × 2 × 1 = 3628800,
-    Thirty days has September,
+    and the sum of the digits in the number 10! is 3 + 6 + 2 + 8 + 8 + 0 + 0 = 27.
-    April, June and November.
-    All the rest have thirty-one,
-    Saving February alone,
-    Which has twenty-eight, rain or shine.
-    And on leap years, twenty-nine.
-    A leap year occurs on any year evenly divisible by 4, but not on a century unless it is divisible by 400.
-    How many Sundays fell on the first of the month during the twentieth century (1 Jan 1901 to 31 Dec 2000)?
 
-    https://projecteuler.net/problem=19
+    Find the sum of the digits in the number 100!
-*/
-
-enum Month {JANUARY=1,FEBRUARY,MARCH,APRIL,MAY,JUNE,JULY,AUGUST,SEPTEMBER,OCTOBER,NOVEMBER,DECEMBER};
 
-int DaysInMonth(enum Month month,int year) {
-    switch (month) {
-        case JANUARY:
-        case MARCH:
-        case MAY:
-        case JULY:
-        case AUGUST:
-        case OCTOBER:
-        case DECEMBER:{
-            return 31;
-        }break;
-        case APRIL:
-        case JUNE:
-        case SEPTEMBER:
-        case NOVEMBER:{
-            return 30;
-        }break;
-        case FEBRUARY:{
-            return ((year%100==0)&&(year%400!=0))?28:(year%4==0)?29:28;
-        }break;
-    }
-}
 
+    https://projecteuler.net/problem=20
+*/
 int main(int argc,char**argv) {
-    int day=1;
+    struct String factorialSum = {1,"0"};
-    enum Month month=1;
+    int counter=1;
-    int year=1900;
+    mult((struct String){3,"575"},(struct String){4,"4200"});
-    enum Weekday{
+    while (counter<=100) {
-        SUNDAY,
+        counter++;
-        MONDAY,
-        TUESDAY,
-        WEDNESDAY,
-        THURSDAY,
-        FRIDAY,
-        SATURDAY,
-    } weekday=MONDAY;
-
-    int sundayCount=0;
-
-    while((day!=31)||(month!=12)||(year!=2000)) {
-        printf("Date: %d/%d/%d\n",month,day,year);
-        if (year>=1901) {
-            //Start counting Sundays.
-            if (weekday==SUNDAY&&day==1) {
-                sundayCount++;
-            }
-        }
-        //Increment the day.
-        if (day+1<=DaysInMonth(month,year)) {
-            day++;
-        } else 
-        if (month+1<=12){
-            //It's a new month.
-            month++;
-            day=1;
-        } else {
-            //It's a new year!
-            year++;
-            day=1;
-            month=1;
-            //printf("The year is now %d...\n",year);
-        }
-        weekday=((weekday+1)<=SATURDAY)?weekday+1:SUNDAY;
     }
 
-    printf("\n\n%d Sundays were on the 1st of the month.",sundayCount);
     return 0;
 }

src/utils.c

@@ -2,6 +2,26 @@
 #include <stdio.h>
 #include <stdlib.h>
 
+struct String mult(struct String numb1, struct String numb2) {
+    struct String n1 = numb1;
+    struct String n2 = numb2;
+    byte carryover = -1;
+    if (numb2.length>numb1.length) {
+        n1=numb2;
+        n2=numb1;
+    }
+    int addends[n2.length][n1.length+1];
+    for (int i=0;i<n2.length;i++) {
+        for (int j=0;j<n1.length+1;j++) {
+            addends[i][j]=0;
+        }
+    }
+    printIntDoubleArr(n2.length,n1.length+1,addends);
+    for (int i=n2.length-1;i>=0;i--) {
+        
+    }
+}
+
 struct String add(struct String numb1, struct String numb2){
     byte carryover=0;
     int digitCount=0;

src/utils.h

@@ -7,5 +7,6 @@ struct String{
     char*str;
 };
 struct String add(struct String numb1, struct String numb2);
+struct String mult(struct String numb1, struct String numb2);
 void printLongDoubleArr(int a,int b,long doubleArr[a][b]);
 void printIntDoubleArr(int a,int b,int doubleArr[a][b]);