Simple tool to brute force 3x+1 for a new loop.
docs: explained >> in comment
+28
-5
+6
.idea/vcs.xml
+6
.idea/vcs.xml
···
1
1
<?xml version="1.0" encoding="UTF-8"?>
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2
<project version="4">
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+
<component name="CommitMessageInspectionProfile">
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+
<profile version="1.0">
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+
<inspection_tool class="CommitFormat" enabled="true" level="WARNING" enabled_by_default="true" />
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<inspection_tool class="CommitNamingConvention" enabled="true" level="WARNING" enabled_by_default="true" />
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</profile>
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</component>
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<component name="VcsDirectoryMappings">
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<mapping directory="$PROJECT_DIR$" vcs="Git" />
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</component>
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-5
src/main.rs
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-5
src/main.rs
···
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largest_num = current_num;
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}
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-
current_num = current_num.mul(3) + 1; // For some reason using .mul() is faster then * but .add() is slightly slower then +. it was only a few ms slower to do all 50K but on an extremely large scale it matters
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+
// For some reason using .mul() is faster then * but .add() is slightly slower then +.
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+
// it was only a few ms slower to do all 50K but on an extremely large scale it matters.
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+
current_num = current_num.mul(3) + 1;
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+
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} else {
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if current_num < smallest_num{
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smallest_num = current_num;
···
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largest_num = current_num;
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}
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-
current_num = current_num >> 1; // Divides by 2 a bit faster
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// Writing this one line taught me about bit shifting.
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// doing >> on an unsigned integer (u8-u16-u32-u64-u128) does something called
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// Logical Right Shifting. This removes the least significant bit or the right most
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// bit and places a 0 on the left. so the binary form of 8 is 1000, doing 8>>1 shifts
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// the bits to the right once, this takes the last 0 and removes it making it 100, we
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// then add a new 0 to the left making it 0100 which is binary for 4.
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// This is more efficient then just trying to do division because there is no actual
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// math involved and just a super quick bit operation.
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//
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// Another example:
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// 69420 >> 1 == 34710
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// 0001 0000 1111 0010 1100 >> 1
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// 0001 0000 1111 0010 110
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// 0000 1000 0111 1001 0110 == 34710
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//
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+
current_num = current_num >> 1;
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}
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if current_num == smallest_num {
···
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125
let mut smallest_num_count = 1;
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while smallest_num_count != 2{
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127
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-
// if odd
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if current_num % 2 != 0 {
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if current_num < smallest_num{
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smallest_num = current_num;
···
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136
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event!(Level::INFO, "{} is odd. Smallest number: {}. Largest number: {}", current_num, smallest_num, largest_num);
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-
current_num = current_num.mul(3) + 1; // For some reason using .mul() is faster then * but .add() is slightly slower then +. it was only a few ms slower to do all 50K but on an extremely large scale it matters
139
+
current_num = current_num.mul(3) + 1;
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} else {
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if current_num < smallest_num{
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smallest_num = current_num;
···
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148
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event!(Level::INFO, "{} is even. Smallest number: {}. Largest number: {}", current_num, smallest_num, largest_num);
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-
current_num = current_num >> 1; // Divides by 2 a bit faster
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+
current_num = current_num >> 1;
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}
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if current_num == smallest_num {