Added bigint header file and edited the solution to include bigint to correctly handle the large numbers

projecteuler/065/main.cpp

@@ -0,0 +1,77 @@
+// Find the sum of digits in the numerator of the 100th convergent of the continued fraction for e.
+// Probably good to know that e can be written as [2; 1, 2, 1, 1, 4, 1, 1, 6, 1, ..., 1, 2k, 1, ...]
+
+#include <bits/stdc++.h>
+#include "../bigint.h"
+
+using namespace std;
+
+InfInt gcd(InfInt a, InfInt b){
+    if(b == 0){
+        return a;
+    }
+    return gcd(b, a % b);
+}
+
+pair<InfInt, InfInt> fracAdd(const pair<InfInt, InfInt>& f1, const pair<InfInt, InfInt>& f2){
+    pair<InfInt, InfInt> result = {f1.first*f2.second + f2.first*f1.second, f1.second * f2.second};
+    InfInt g = gcd(result.first, result.second);
+
+    result.first /= g;
+    result.second /= g;
+
+    return result;
+}
+
+pair<InfInt, InfInt> fracInv(const pair<InfInt, InfInt>& f){
+    return pair<InfInt, InfInt>(f.second, f.first);
+}
+
+pair<InfInt, InfInt> cfApprox(const vector<int>& seq){
+    pair<InfInt, InfInt> result = {seq[0], 1};
+    pair<InfInt, InfInt> carry = {0, 1};
+    if(seq.size() > 1){
+        carry = {1, seq[1]};
+        for(size_t i = seq.size() - 2; i > 0; --i){
+            pair<InfInt, InfInt> newp = {seq[i], 1};
+            carry = fracInv(fracAdd(carry, newp));
+        }
+    }
+
+    result = fracAdd(result, carry);
+
+    return result;
+}
+
+int main(){
+
+    cout << "HeInfInto this is Patrick" << endl;
+    auto start = chrono::high_resolution_clock::now();
+
+    // Generate the e sequence
+    vector<int> seq;
+    seq.push_back(2);
+    for(int i = 0; i < 99; ++i){
+        if(i % 3 == 0 || i % 3 == 2){
+            seq.push_back(1);
+        } else{
+            seq.push_back(((i / 3) + 1) * 2);
+        }
+    }
+
+    auto f = cfApprox(seq);
+    InfInt frac = f.first;
+    InfInt result = 0;
+    
+    while(frac > 0){
+        result += frac % 10;
+        frac /= 10;
+    }
+
+    cout << "Fraction of " << f.first << " / " << f.second << " resulting in sum of: ";
+    cout << result << endl;
+
+    auto duration = chrono::duration_cast<chrono::milliseconds>(chrono::high_resolution_clock::now() - start);
+    cout << (float)duration.count()/1000 << endl;
+    return 0;
+}