71 lines
1.4 KiB
JavaScript
71 lines
1.4 KiB
JavaScript
/**
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* File: iteration.js
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* Created Time: 2023-08-28
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* Author: Gaofer Chou (gaofer-chou@qq.com)
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*/
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/* for loop */
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function forLoop(n) {
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let res = 0;
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// Loop sum 1, 2, ..., n-1, n
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for (let i = 1; i <= n; i++) {
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res += i;
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}
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return res;
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}
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/* while loop */
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function whileLoop(n) {
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let res = 0;
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let 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++; // Update condition variable
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}
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return res;
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}
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/* while loop (two updates) */
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function whileLoopII(n) {
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let res = 0;
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let 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++;
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i *= 2;
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}
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return res;
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}
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/* Double for loop */
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function nestedForLoop(n) {
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let res = '';
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// Loop i = 1, 2, ..., n-1, n
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for (let i = 1; i <= n; i++) {
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// Loop j = 1, 2, ..., n-1, n
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for (let j = 1; j <= n; j++) {
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res += `(${i}, ${j}), `;
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}
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}
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return res;
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}
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/* Driver Code */
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const n = 5;
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let res;
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res = forLoop(n);
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console.log(`for 循环的求和结果 res = ${res}`);
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res = whileLoop(n);
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console.log(`while 循环的求和结果 res = ${res}`);
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res = whileLoopII(n);
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console.log(`while 循环（两次更新）求和结果 res = ${res}`);
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const resStr = nestedForLoop(n);
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console.log(`双层 for 循环的遍历结果 ${resStr}`);
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