列置换算法的C语言实现
时间: 2023-05-18 07:06:48 浏览: 53
以下是列置换算法的C语言实现:
```
#include <stdio.h>
void columnarTransposition(char *key, char *plaintext) {
int keyLength = strlen(key);
int plaintextLength = strlen(plaintext);
// Calculate number of rows required
int rows = plaintextLength / keyLength;
if (plaintextLength % keyLength != 0) {
rows++;
}
// Create matrix to hold plaintext
char matrix[rows][keyLength];
// Fill matrix with plaintext
int index = 0;
for (int i = 0; i < rows; i++) {
for (int j = 0; j < keyLength; j++) {
if (index < plaintextLength) {
matrix[i][j] = plaintext[index];
index++;
} else {
matrix[i][j] = ' ';
}
}
}
// Print matrix
printf("Matrix:\n");
for (int i = 0; i < rows; i++) {
for (int j = 0; j < keyLength; j++) {
printf("%c ", matrix[i][j]);
}
printf("\n");
}
// Create array to hold column order
int order[keyLength];
for (int i = 0; i < keyLength; i++) {
order[i] = i;
}
// Sort column order based on key
for (int i = 0; i < keyLength - 1; i++) {
for (int j = i + 1; j < keyLength; j++) {
if (key[i] > key[j]) {
// Swap columns
int temp = order[i];
order[i] = order[j];
order[j] = temp;
}
}
}
// Print column order
printf("Column Order: ");
for (int i = 0; i < keyLength; i++) {
printf("%d ", order[i]);
}
printf("\n");
// Print ciphertext
printf("Ciphertext: ");
for (int i = 0; i < keyLength; i++) {
for (int j = 0; j < rows; j++) {
printf("%c", matrix[j][order[i]]);
}
}
printf("\n");
}
int main() {
char key[] = "SECRET";
char plaintext[] = "THIS IS A SECRET MESSAGE";
columnarTransposition(key, plaintext);
return 0;
}
```
希望这个实现对你有帮助!