为什么我的算法返回“-1”意味着目标值 73 不在数组中? (当数组中显然有 73 时)。 [这是来自可汗学院,但没有帮助]
它应该返回数组中位置的索引, 如果数组不包含目标值,则为“-1”
Var doSearch = function(array, targetValue) {
var min = 0;
var max = array.length - 1;
var guess;
while(max >= min) {
guess = floor((max*1 + min*1) / 2);
if (guess === targetValue) {
return guess;
} else if (guess < targetValue) {
min = guess + 1;
} else {
max = guess - 1;
}
}
return -1;
};
var primes = [2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37,
41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97];
var result = doSearch(primes, 73);
println("Found prime at index " + result);
最佳答案
您将 guess
设置为数组索引,但随后您将其与 targetValue
进行比较。您需要比较该索引处的数组元素。
var doSearch = function(array, targetValue) {
var min = 0;
var max = array.length - 1;
var guess;
var guessvalue;
while (max >= min) {
guess = Math.floor((max * 1 + min * 1) / 2);
guessValue = array[guess];
if (guessValue === targetValue) {
return guess;
} else if (guessValue < targetValue) {
min = guess + 1;
} else {
max = guess - 1;
}
}
return -1;
};
var primes = [2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37,
41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97
];
var result = doSearch(primes, 73);
console.log("Found prime at index " + result);
关于javascript - 为什么我的算法无法在我的数组中找到索引?,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/50867667/