自分専用、2桁、3桁、4桁で数字の前に「0」ゼロを付ける。

いろいろ、注意

• UNO での　予定は、未定

プログラム

オンラインコンパイラpaiza

#include <iostream>
using namespace std;

void z4(char *str){
    if(str[0] == 0) return;
    if(str[1] == 0) {
        str[4] = 0;
        str[3] = str[0];
        str[2] = '0';
        str[1] = '0';
        str[0] = '0';
        return;
    }
    if(str[2] == 0) {
        str[4] = 0;
        str[3] = str[1];
        str[2] = str[0];
        str[1] = '0';
        str[0] = '0';
        return;
    }
    if(str[3] == 0) {
        str[4] = 0;
        str[3] = str[2];
        str[2] = str[1];
        str[1] = str[0];
        str[0] = '0';
        return;
    }
}

void z3(char *str){
    if(str[0] == 0) return;
    if(str[1] == 0) {
        str[3] = 0;
        str[2] = str[0];
        str[1] = '0';
        str[0] = '0';
        return;
    }
    if(str[2] == 0) {
        str[3] = 0;
        str[2] = str[1];
        str[1] = str[0];
        str[0] = '0';
        return;
    }
}

void z2(char *str){
    if(str[0] == 0) return;
    if(str[1] == 0) {
        str[2] = 0;
        str[1] = str[0];
        str[0] = '0';
        return;
    }
}

int main(void){
    // Your code here!
    char a1[16] =    "1";z4(a1);printf(a1);printf("\n");
    char a2[16] =   "12";z4(a2);printf(a2);printf("\n");
    char a3[16] =  "123";z4(a3);printf(a3);printf("\n");
    char a4[16] = "1234";z4(a4);printf(a4);printf("\n");

    char b1[16] =    "1";z3(b1);printf(b1);printf("\n");
    char b2[16] =   "12";z3(b2);printf(b2);printf("\n");
    char b3[16] =  "123";z3(b3);printf(b3);printf("\n");

    char c1[16] =    "1";z2(c1);printf(c1);printf("\n");
    char c2[16] =   "12";z2(c2);printf(c2);printf("\n");
}

0001
0012
0123
1234
001
012
123
01
12