sigonasr2
/
ProjectEuler
1
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

Finally creating iterative repeating sequence counter and optimized for prime factors

Browse Source 
Co-authored-by: sigonasr2 <sigonasr2@gmail.com>
main
sigonasr2, Sig, Sigo 2 years ago
parent 6ca700a8ef
commit 3ea3137f8a
3 changed files with 211 additions and 34 deletions
Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL
Show Stats Download Patch File Download Diff File
  1. BIN
      current
  2. 1
      p022_names.txt
  3. 244
      src/main.c

BIN
current
View File

Binary file not shown.

1
p022_names.txt
View File

File diff suppressed because one or more lines are too long

244
src/main.c
Unescape View File

@ -3,42 +3,220 @@
#include <stdlib.h>
/*
The Fibonacci sequence is defined by the recurrence relation:
Fn = Fn−1 + Fn−2, where F1 = 1 and F2 = 1.
Hence the first 12 terms will be:
F1 = 1
F2 = 1
F3 = 2
F4 = 3
F5 = 5
F6 = 8
F7 = 13
F8 = 21
F9 = 34
F10 = 55
F11 = 89
F12 = 144
The 12th term, F12, is the first term to contain three digits.
What is the index of the first term in the Fibonacci sequence to contain 1000 digits?
https://projecteuler.net/problem=24
A unit fraction contains 1 in the numerator. The decimal representation of the unit fractions with denominators 2 to 10 are given:
1/2 = 0.5
1/3 = 0.(3)
1/4 = 0.25
1/5 = 0.2
1/6 = 0.1(6)
1/7 = 0.(142857)
1/8 = 0.125
1/9 = 0.(1)
1/10 = 0.1
Where 0.1(6) means 0.166666..., and has a 1-digit recurring cycle. It can be seen that 1/7 has a 6-digit recurring cycle.
Find the value of d < 1000 for which 1/d contains the longest recurring cycle in its decimal fraction part.
https://projecteuler.net/problem=26
*/
boolean isPrime(int*primeList,int primeListSize,int numb) {
for (int i=0;i<primeListSize;i++) {
if (numb==primeList[i]) {
return true;
}
}
return false;
}
int*getFactors(int numb) {
int*factorList=malloc(sizeof(int)*1);
int factorListSize=2;
factorList[0]=1;
factorList[1]=numb;
int max=numb;
for (int i=2;i<max;i++) {
if (numb%i==0) {
factorList=realloc(factorList,sizeof(int)*++factorListSize);
factorList[factorListSize-1]=i;
}
if (numb/i!=i) {
factorList=realloc(factorList,sizeof(int)*++factorListSize);
factorList[factorListSize-1]=numb/i;
max=numb/i;
}
}
factorList=realloc(factorList,sizeof(int)*++factorListSize);
factorList[factorListSize-1]=0;
return factorList;
}
boolean isFactor(int*factorList,int numb) {
int counter=0;
while (factorList[counter]!=0) {
if (numb==factorList[counter]) {
return true;
}
counter++;
}
return false;
}
boolean isFactorMinusOne(int*factorList,int numb) {
int counter=0;
while (factorList[counter]!=0) {
if (numb==factorList[counter]) {
return true;
}
counter++;
}
return false;
}
const int TARGET_REPEATS_REQUIRED=100000;
int main(int argc,char**argv) {
struct String numb1 = BigNumber(1);
struct String numb2 = BigNumber(1);
int term=3;
while (numb2.length<1000) {
struct String oldString = numb1;
numb1 = numb2;
numb2 = add(oldString,numb1);
//free(oldString.str);
//printf("%d: %s\n",term,numb2.str);
term++;
int divider=0;
int divisor=997;
int sequence[TARGET_REPEATS_REQUIRED]; //Let's assume for the sake of sanity that 100000 repeating digits is enough. I sure hope so.
int sequenceLength=0;
int sequenceRepeat=0;
int sequenceMarker=-1;
int longestCycleLength=0;
int longestCycleDivisor=0;
int longestSequence[TARGET_REPEATS_REQUIRED/10];
int*primeList=malloc(sizeof(int)*0);
int primeListSize=0;
FILE*f = fopen("archives/primegenerator/primes","r");
while (fgetc(f)!='{');
while (true) {
char c;
int digit=0;
while ((c=fgetc(f))!=',') {
digit*=10;
digit+=c-'0';
}
if (digit>=1000) {
break;
} else {
primeList=realloc(primeList,sizeof(int)*++primeListSize);
primeList[primeListSize-1]=digit;
}
}
while (divisor<999) {
divider=10; //We always start with 10.
sequenceLength=0;
sequenceRepeat=0;
for (int i=0;i<sequenceLength;i++) {
sequence[i]=0;
}
sequenceMarker=-1;
while (sequenceLength<TARGET_REPEATS_REQUIRED) {
int result=divider/divisor;
//printf("%d/%d = %d\n",divider,divisor,result);
divider=divider%divisor;
sequence[sequenceLength++]=result;
divider*=10;
if (divider==0) {
//We're solved.
break;
}
}
/*printf("%d:",divisor);
for (int i=0;i<sequenceLength;i++) {
printf("%d",sequence[i]);
}
printf("\n");*/
//We need to look at all combinations of possible repeating sequences.
//Starting from iteration loop of length 1, and an offset incrementing by 1, see if anything remains the same.
//Then do this for iteration loop of length 2, offset incrementing by 1, etc.
//Find it repeating at least 20 times to assume it repeats infinitely.
boolean isP = isPrime(primeList,primeListSize,divisor);
int*factors = getFactors(divisor);
int counter=0;
/*if (isP) {
printf("Factors of %d:",divisor);
while (factors[counter]!=0) {
printf("%d,",factors[counter]);
counter++;
}
printf("\n");
}*/
boolean matched=false;
if (sequenceLength==TARGET_REPEATS_REQUIRED) {
for (int checkLength=0;checkLength<TARGET_REPEATS_REQUIRED/10;checkLength++) {
if (isP&&!isFactorMinusOne(factors,checkLength+1)) {continue;}
for (int offset=0;offset<sequenceLength+1-checkLength;offset++) {
int sequenceStore[checkLength+1];
int requiredCheckAmt=TARGET_REPEATS_REQUIRED/10-2;
for (int i=0;i<checkLength+1;i++) {
sequenceStore[i]=sequence[i+offset];
/*printf("%d:",divisor);
for (int i=0;i<checkLength+1;i++) {
printf("%d",sequenceStore[i]);
}
0010030090270812437311935807422266800401203610832497492477432296890672016048144433299899699097291875626880641925777331995987963891675025075225677031093279839518555667
0010030090270812437311935807422266800401203610832497492477432296890672016048144433299899699097291875626880641925777331995987963891675025075225677031093279839518555667
printf("\n");*/
}
//Now if this repeating sequence can be found requiredCheckAmt times, we're golden.
boolean allMatching=true;
int currentOffset=0;
int found=0;
while (requiredCheckAmt>0&&found<20) {
for (int i=0;i<checkLength+1;i++) {
//printf(" Compare %d to %d\n",sequence[offset+currentOffset+checkLength+1+i],sequenceStore[i]);
if (sequence[offset+currentOffset+checkLength+1+i]!=sequenceStore[i]) {
allMatching=false;
goto check;
}
}
requiredCheckAmt--;
currentOffset+=checkLength+1;
found++;
//printf("Found a repeat.");
}
check:
if (allMatching) {
printf("Longest repeating sequence for %d is of length %d: ",divisor,checkLength+1);
for (int i=0;i<checkLength+1;i++) {
printf("%d",sequenceStore[i]);
}
printf("\n");
if (longestCycleLength<checkLength+1) {
longestCycleLength=checkLength+1;
longestCycleDivisor=divisor;
for (int i=0;i<longestCycleLength;i++) {
longestSequence[i]=sequenceStore[i];
}
}
matched=true;
goto next;
}
}
}
} else {
matched=true;
printf("Longest repeating sequence for %d is of length 0.\n",divisor);
}
next:
free(factors);
if (!matched) {
printf("Not enough data to calculate longest repeating sequence for %d!\nQuitting...\n",divisor);
return 1;
}
divisor++;
}
printf("\n\nThe largest repeating sequence length is from %d with %d in length.",longestCycleDivisor,longestCycleLength);
printf("\n\tSequence: ");
for (int i=0;i<longestCycleLength;i++) {
printf("%d",longestSequence[i]);
}
printf("\n\nTerm %d has %d digits!",term,numb2.length);
printf("\n");
return 0;
}
Write Preview
Loading…
Cancel
Save