我有一个示例HTML,它是从PracticalCryptography.com获得的,可以帮助我计算随机文本的重合度索引
<html>
<body>
<script type="text/javascript">
function GetIC() {
plaintext = document.getElementById("p").value.toLowerCase().replace(/[^a-z]/g, "");
var counts = new Array(26);
var totcount = 0;
for (i = 0; i < 26; i++) counts[i] = 0;
for (i = 0; i < plaintext.length; i++) {
counts[plaintext.charCodeAt(i) - 97] ++;
totcount++;
}
var sum = 0;
for (i = 0; i < 26; i++) sum = sum + counts[i] * (counts[i] - 1);
ic = sum / (totcount * (totcount - 1));
document.getElementById("ic").value = ic;
document.getElementById("count").value = totcount;
}
</script>
<form>
<p>
<textarea name="p" id="p" rows="2" cols="50" wrap="soft">Defend the east wall of the castle</textarea>
</p>
<p>
<input name="b" id="b" value="Get I.C." onclick="GetIC()" type="button">
</p>
<p>Index of Coincidence =
<input id="ic" name="ic" size="15" maxchars="15" value="" type="text">Character Count =
<input id="count" name="count" size="8" maxchars="8" value="" type="text">
</p>
</form>
</body>
</html>
我想将Javascript代码移植到Java。以下是我的尝试:
private static boolean TestIOC(String text) {
// Replace any character *not* in the range a-z
// /g -- global tag means find all, not just find one
String plaintext = text.toLowerCase().replaceAll("/[^a-z]/g", "");
int counts[] = new int[26];
int totcount = 0;
for (int i = 0; i < 26; i++) counts[i] = 0;
for (int i = 0; i < plaintext.length(); i++) {
int codePointAtI = Character.codePointAt(plaintext, i);
//System.out.println(codePointAtI);
counts[codePointAtI - 97]++; // Problematic line
totcount++;
}
int sum = 0;
float ic = 0;
for (int i = 0; i < 26; i++) {
sum = sum + counts[i]*(counts[i]-1);
ic = sum / (totcount*(totcount-1));
}
if (ic >= 0.062 || ic <= 0.072) {
DecimalFormat df = new DecimalFormat("#.###");
System.out.println(df.format(ic));
return true;
}
else {
return false;
}
}
但是它有一个
在
counts[codePointAtI - 97]++;
纯文本输出
注释行的输出:System.out.println(codePointAtI);
最佳答案
private static boolean TestIOC(String text) {
// Replace any character *not* in the range a-z, and change all characters to lowercase.
String plaintext = text.toLowerCase().replaceAll("[^a-z]", "");
//System.out.println(plaintext);
int counts[] = new int[26];
int totcount = 0;
double sum = 0;
double ic = 0;
for (int i = 0; i < 26; i++) counts[i] = 0;
for (int i = 0; i < plaintext.length(); i++) {
int codePointAtI = Character.codePointAt(plaintext, i);
//System.out.println(codePointAtI);
counts[codePointAtI - 97]++;
totcount++;
}
//System.out.println("Totcount: " + totcount);
for (int i = 0; i < 26; i++) {
sum = sum+counts[i]*(counts[i]-1);
ic = sum/(totcount*(totcount-1));
}
//System.out.println("Sum:" + sum);
//System.out.println("ic: " + ic);
if (ic >= 0.059 && ic <= 0.068) {
System.out.println("This file contains an English text.");
return true;
}
else {
System.out.println("This file does not contain an English text.");
return false;
}
}