add sieveoferatosthenes

Author: Adityasinghvats

31Greedy/04_lc1710.cpp

@@ -0,0 +1,30 @@
+#include<bits/stdc++.h>
+using namespace std;
+bool cmp(vector<int> &a, vector<int>& b){
+    return a[1]>b[1];
+}
+/*
+Tc - O(n log n)
+*/
+        int maximumUnits(vector<vector<int>>& boxTypes, int truckSize) {
+            int n = boxTypes.size();
+        
+            sort(boxTypes.begin(), boxTypes.end(), cmp);
+            int profit = 0;
+            for(int i=0;i<n;i++){
+                if(boxTypes[i][0] <= truckSize){
+                    profit += boxTypes[i][0] * boxTypes[i][1];
+                    truckSize -= boxTypes[i][0];
+                }else{
+                    profit += truckSize * boxTypes[i][1];
+                    truckSize = 0;
+                    break;
+                }
+            }
+            return profit;
+        }
+int main(){
+    vector<vector<int>> boxTypes = {{5,10},{2,5},{4,7},{3,9}};
+    cout<<"maximum units on truck can be: "<<maximumUnits(boxTypes, 10)<<" units";
+    return 0;
+}

31Greedy/04_lc1710.exe

@@ -0,0 +1,101 @@
+#include<bits/stdc++.h>
+using namespace std;
+//find first prime
+// int fPrime(vector<int> &arr){
+//     for(int i=0;i<arr.size();i++){
+//         if (arr[i] <= 1) continue;
+//         if(arr[i] == 2) return i;
+//         if(arr[i] == 3) return i;
+//         if (arr[i] % 2 == 0 || arr[i] % 3 == 0) {
+//             continue;
+//         } 
+//         // Iterate from 5 up to the square root of n
+//         // We only need to check divisibility by numbers of the form 6k ± 1
+//         for (int j = 5; j * j <= arr[i]; j = j + 6) {
+//             if (arr[i] % j == 0 || arr[i] % (j + 2) == 0) {
+//                 continue;
+//             }
+//         }
+//         return i;
+//     }
+//     return 0;
+// }
+// //iterate and mark all mutiples of first prime Number
+// void mark(vector<int> &arr, int firstidx){
+//     //mark -1
+//     for(int i=firstidx+1;i<arr.size();i++){
+//         if(arr[i] % arr[firstidx] == 0){
+//             arr[i] = -1;
+//         }
+//     }
+// }
+// int main(){
+//     vector<int>arr = {2,3,4,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20};
+//     int firstPrimeIdx = fPrime(arr);
+//     cout<<firstPrimeIdx<<endl;
+//     //edge case
+//     for(int i=0;i<firstPrimeIdx;i++){
+//         arr[i] = -1;
+//     }
+//     //start marking multiples
+//     while(firstPrimeIdx<arr.size()){
+//         if(arr[firstPrimeIdx] != -1){
+//             mark(arr, firstPrimeIdx);
+//         }
+//         firstPrimeIdx++;
+//     }
+//     for(auto ele:arr){
+//         cout<<ele<<" ";
+//     }
+//     cout<<endl;
+//     cout<<"All prime numbers are:"<<endl;
+//     for(auto ele:arr){
+//         if (ele != -1) cout<<ele<<" ";
+//     }
+//     cout<<endl;
+
+//     return 0;
+// }
+
+vector<int> sieveOfEratosthenes(int n) {
+    vector<bool> isPrime(n + 1, true);
+    // 0 and 1 are not prime numbers
+    isPrime[0] = isPrime[1] = false;
+    
+    // Iterate up to the square root of n
+    for (int p = 2; p * p <= n; ++p) {
+        // If isPrime[p] is not changed, then it is a prime
+        if (isPrime[p]) {
+            // multiples which are less than p*p are already been marked.
+            // i = 2, 4, 6, 8, 10
+            for (int i = p * p; i <= n; i += p) {
+                isPrime[i] = false;
+            }
+        }
+    }
+    // Store all prime numbers in a vector
+    vector<int> primes;
+    for (int p = 2; p <= n; ++p) {
+        if (isPrime[p]) {
+            primes.push_back(p);
+        }
+    }
+    return primes;
+}
+
+int main() {
+    int n;
+
+    cout << "Enter the upper limit: ";
+    cin >> n;
+
+    vector<int> primeNumbers = sieveOfEratosthenes(n);
+
+    cout << "Prime numbers up to " << n << " are: ";
+    for (int prime : primeNumbers) {
+        cout << prime << " ";
+    }
+    cout <<endl;
+
+    return 0;
+}