#include <stdio.h>
#include <string.h>
 
void decrypt_caesar(char *ciphertext, int shift) {
    int i;
    char ch;
    int len = strlen(ciphertext);
 
    for (i = 0; i < len; i++) {
        ch = ciphertext[i];
        ch = ch - shift;  
        printf("%c", ch);
    }
    printf("\n");
}
 
int main() {
 
    char ciphertext[] = "mcpciyvcfckicmw";
    int shift = 34;  // シフト値
 
    printf("復号された文字列: ");
    decrypt_caesar(ciphertext, shift);
 
    return 0;
}
 

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