75 lines
1.5 KiB
Rust
75 lines
1.5 KiB
Rust
/*
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* File: iteration.rs
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* Created Time: 2023-09-02
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* Author: night-cruise (2586447362@qq.com)
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*/
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/* for loop */
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fn for_loop(n: i32) -> i32 {
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let mut res = 0;
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// Loop sum 1, 2, ..., n-1, n
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for i in 1..=n {
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res += i;
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}
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res
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}
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/* while loop */
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fn while_loop(n: i32) -> i32 {
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let mut res = 0;
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let mut i = 1; // Initialize condition variable
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// Loop sum 1, 2, ..., n-1, n
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while i <= n {
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res += i;
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i += 1; // Update condition variable
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}
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res
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}
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/* while loop (two updates) */
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fn while_loop_ii(n: i32) -> i32 {
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let mut res = 0;
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let mut i = 1; // Initialize condition variable
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// Loop sum 1, 4, 10, ...
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while i <= n {
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res += i;
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// Update condition variable
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i += 1;
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i *= 2;
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}
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res
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}
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/* Double for loop */
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fn nested_for_loop(n: i32) -> String {
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let mut res = vec![];
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// Loop i = 1, 2, ..., n-1, n
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for i in 1..=n {
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// Loop j = 1, 2, ..., n-1, n
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for j in 1..=n {
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res.push(format!("({}, {}), ", i, j));
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}
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}
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res.join("")
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}
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/* Driver Code */
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fn main() {
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let n = 5;
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let mut res;
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res = for_loop(n);
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println!("\nfor loop sum result res = {res}");
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res = while_loop(n);
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println!("\nwhile loop sum result res = {res}");
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res = while_loop_ii(n);
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println!("\nwhile loop (updated twice) sum result res = {}", res);
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let res = nested_for_loop(n);
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println!("\nDouble for loop traversal result {res}");
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}
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