// This script computes sum of prime numbers up to the given value // Press "Compile and Run" to see the results of the computation // // An optimized version of the Sieve of Eratosthenes is used to identify and sum the prime numbers. // // The code will run on a Mindustry processor too, albeit quite slowly. // Program parametrization param MEMORY = bank1; // Available in emulated environment param VALUE = 5000; // Use a value between 0 and 49150 // Number of bits to store in a single memory slot // Since Mindustry Logic stores the values as double, not all 64 bits can be used. const MOD = 48; // We need to declare linked blocks we'll use // This one is used to output messages onto linked message1; begin // Need to clear the bank at the beginning for var i in 0 ... 512 do MEMORY[i] = 0; end; var result = sumPrimesUpTo(VALUE); print("The sum of all primes between 0 and "); printNumber(VALUE); print(" is "); printNumber(result); print("."); printflush(message1); end; void setBit(bitIndex) MEMORY[bitIndex \ MOD] |= (1 << (bitIndex % MOD)); end; def getBit(bitIndex) MEMORY[bitIndex \ MOD] & (1 << (bitIndex % MOD)); end; def testAndSetMultiples(n, maximum) var result; if result = !getBit(n \ 2) then var max = maximum \ 2; for var i = n * n \ 2 ; i <= max ; i += n do setBit(i); end; end; result; end; def sumPrimesUpTo(maximum) if maximum < 3 then return maximum & 2; end; var sum = 2 + 3; var i = 5; var sqrtMax = ceil(sqrt(maximum)); while i <= sqrtMax do if testAndSetMultiples(i, maximum) then sum += i; end; i += 2; if testAndSetMultiples(i, maximum) then sum += i; end; i += 4; end; while i <= maximum do if !getBit(i \ 2) then sum += i; end; i += 2; if !getBit(i \ 2) then if i <= maximum then sum += i; end; end; i += 4; end; sum; end; // Prints the number using a comma as a thousands separator // Uses the memory to split the number into individual digits // It prints the number instead of returning the generated string, // because Mindustry Logic doesn't support string operations. void printNumber(n) var index = 0; var decimal = 0; while true do MEMORY[index] = n % 10; n \= 10; index++; decimal++; if n <= 0 then break; end; if decimal % 3 == 0 then MEMORY[index++] = 10; // represents the comma end; end; while index-- > 0 do print(MEMORY[index] == 10 ? "," : MEMORY[index]); end; end;