C 解法, 执行用时: 2ms, 内存消耗: 376KB, 提交时间: 2020-05-23

#include<stdio.h>
#include<math.h>
#include<stdlib.h>
#include<string.h>
const int MAXV = 1010;
int n, cnt;
char password[MAXV], ans[MAXV];
int a[MAXV];
void DFS(int x, int index) {
    if(x == n) {
        if(cnt)
            printf(" ");
        ans[index] = '\0';
        printf("%s", ans);
        cnt++;
    }
    if(a[x] == 0)
        return;
    if(a[x] >= 3 || x == n - 1 || (a[x] == 2 && a[x + 1] > 6)) {
        ans[index] = 'a' + a[x] - 1;
        DFS(x + 1, index + 1);
    }
    else {
        ans[index] = a[x] - 1 + 'a';
        DFS(x + 1, index + 1);
        ans[index] = 10 * a[x]+a[x+1] - 1 + 'a';
        DFS(x + 2, index + 1);
    }
}
   
int main() {
    while(scanf("%s", password) != EOF) {
        n = strlen(password);
        for(int i = 0; i < n; i++)
            a[i] = password[i] - '0';
        cnt = 0;
        DFS(0, 0);
        printf("\n");
    }
    return 0;
}

C 解法, 执行用时: 2ms, 内存消耗: 376KB, 提交时间: 2020-05-20

#include<stdio.h>
#include<math.h>
#include<stdlib.h>
#include<string.h>
const int MAXV = 1010;
int n, cnt;
char password[MAXV], ans[MAXV];
int a[MAXV];
void DFS(int x, int index) {
    if(x == n) {
        if(cnt)
            printf(" ");
        ans[index] = '\0';
        printf("%s", ans);
        cnt++;
    }
    if(a[x] == 0)
        return;
    if(a[x] >= 3 || x == n - 1 || (a[x] == 2 && a[x + 1] > 6)) {
        ans[index] = 'a' + a[x] - 1;
        DFS(x + 1, index + 1);
    } else {
        ans[index] = a[x] - 1 + 'a';
        DFS(x + 1, index + 1);
        ans[index] = 10 * a[x]+a[x+1] - 1 + 'a';
        DFS(x + 2, index + 1);
    }
}
  
int main() {
    //freopen("input.txt", "r", stdin);
    while(scanf("%s", password) != EOF) {
        n = strlen(password);
        for(int i = 0; i < n; i++)
            a[i] = password[i] - '0';
        cnt = 0;
        DFS(0, 0);
        printf("\n");
    }
    return 0;
}

C 解法, 执行用时: 2ms, 内存消耗: 380KB, 提交时间: 2020-05-14

#include<stdio.h>
#include<math.h>
#include<stdlib.h>
#include<string.h>
const int MAXV = 1010;
int n, cnt;
char password[MAXV], ans[MAXV];
int a[MAXV];
void DFS(int x, int index) {
    if(x == n) {
        if(cnt)
            printf(" ");
        ans[index] = '\0';
        printf("%s", ans);
        cnt++;
    }
    if(a[x] == 0)
        return;
    if(a[x] >= 3 || x == n - 1 || (a[x] == 2 && a[x + 1] > 6)) {
        ans[index] = 'a' + a[x] - 1;
        DFS(x + 1, index + 1);
    } else {
        ans[index] = a[x] - 1 + 'a';
        DFS(x + 1, index + 1);
        ans[index] = 10 * a[x]+a[x+1] - 1 + 'a';
        DFS(x + 2, index + 1);
    }
}
 
int main() {
    //freopen("input.txt", "r", stdin);
    while(scanf("%s", password) != EOF) {
        n = strlen(password);
        for(int i = 0; i < n; i++)
            a[i] = password[i] - '0';
        cnt = 0;
        DFS(0, 0);
        printf("\n");
    }
    return 0;
}

C 解法, 执行用时: 2ms, 内存消耗: 472KB, 提交时间: 2020-05-16

#include<stdio.h>
#include<math.h>
#include<stdlib.h>
#include<string.h>
const int MAXV = 1010;
int n, cnt;
char password[MAXV], ans[MAXV];
int a[MAXV];
void DFS(int x, int index) {
    if(x == n) {
        if(cnt)
            printf(" ");
        ans[index] = '\0';
        printf("%s", ans);
        cnt++;
    }
    if(a[x] == 0)
        return;
    if(a[x] >= 3 || x == n - 1 || (a[x] == 2 && a[x + 1] > 6)) {
        ans[index] = 'a' + a[x] - 1;
        DFS(x + 1, index + 1);
    } else {
        ans[index] = a[x] - 1 + 'a';
        DFS(x + 1, index + 1);
        ans[index] = 10 * a[x]+a[x+1] - 1 + 'a';
        DFS(x + 2, index + 1);
    }
}
   
int main() {
    //freopen("input.txt", "r", stdin);
    while(scanf("%s", password) != EOF) {
        n = strlen(password);
        for(int i = 0; i < n; i++)
            a[i] = password[i] - '0';
        cnt = 0;
        DFS(0, 0);
        printf("\n");
    }
    return 0;
}

C++ 解法, 执行用时: 2ms, 内存消耗: 480KB, 提交时间: 2021-03-13

#include <iostream>
#include <cstring>
#include <cmath>
using namespace std;

string ans = "";
string s;
int len =0;
void dfs (int end){
    if (end == len){
        cout<<ans<<" ";
        return ;
    } 
    int no1 =(int)(s[end]-'0');
    int no2 =(int)(s[end]-'0')*10+(int)(s[end+1]-'0');
    if (no1) {
        char t = 'a'+no1-1;
        ans+=t;
        dfs (end+1);
        ans=ans.substr(0,ans.length()-1);
    }
    if (no2>9&&no2<=26&&end+2<=len){
        char t = 'a'+no2-1;
        ans+=t;
        dfs (end+2);
        ans=ans.substr(0,ans.length()-1);
    }
}

int main (){
    
    while (cin>>s){
        len = s.length();
        dfs(0);
        cout<<endl;
    }
}