Package g0901_1000.s0964_least_operators_to_express_number

Class Solution

java.lang.Object
g0901_1000.s0964_least_operators_to_express_number.Solution
public class Solution extends Object
964 - Least Operators to Express Number.<p>Hard</p> <p>Given a single positive integer <code>x</code>, we will write an expression of the form <code>x (op1) x (op2) x (op3) x ...</code> where each operator <code>op1</code>, <code>op2</code>, etc. is either addition, subtraction, multiplication, or division (<code>+</code>, <code>-</code>, <code>*</code>, or <code>/)</code>. For example, with <code>x = 3</code>, we might write <code>3 * 3 / 3 + 3 - 3</code> which is a value of 3.</p> <p>When writing such an expression, we adhere to the following conventions:</p> <ul> <li>The division operator (<code>/</code>) returns rational numbers.</li> <li>There are no parentheses placed anywhere.</li> <li>We use the usual order of operations: multiplication and division happen before addition and subtraction.</li> <li>It is not allowed to use the unary negation operator (<code>-</code>). For example, &ldquo;<code>x - x</code>&rdquo; is a valid expression as it only uses subtraction, but &ldquo;<code>-x + x</code>&rdquo; is not because it uses negation.</li> </ul> <p>We would like to write an expression with the least number of operators such that the expression equals the given <code>target</code>. Return the least number of operators used.</p> <p><strong>Example 1:</strong></p> <p><strong>Input:</strong> x = 3, target = 19</p> <p><strong>Output:</strong> 5</p> <p><strong>Explanation:</strong> 3 * 3 + 3 * 3 + 3 / 3.</p> <p>The expression contains 5 operations.</p> <p><strong>Example 2:</strong></p> <p><strong>Input:</strong> x = 5, target = 501</p> <p><strong>Output:</strong> 8</p> <p><strong>Explanation:</strong> 5 * 5 * 5 * 5 - 5 * 5 * 5 + 5 / 5.</p> <p>The expression contains 8 operations.</p> <p><strong>Example 3:</strong></p> <p><strong>Input:</strong> x = 100, target = 100000000</p> <p><strong>Output:</strong> 3</p> <p><strong>Explanation:</strong> 100 * 100 * 100 * 100. The expression contains 3 operations.</p> <p><strong>Constraints:</strong></p> <ul> <li><code>2 <= x <= 100</code></li> <li><code>1 <= target <= 2 * 10<sup>8</sup></code></li> </ul>

  • Constructor Details

    • Solution

      public Solution()

  • Method Details

    • leastOpsExpressTarget

      public int leastOpsExpressTarget(int x, int target)