Codeforces, codeforce

Codeforces, codeforce

Jokewithpermutation

Input parameter le: joke. in
Output role le: joke. out
Joey had saved a permutation of integers from 1 to n in a text folder le. All the numbers were written
Decimal numbers without leading spaces.
Then Joe made a practical joke on her: he removed all the spaces in the specified le.
Help Joey to restore the original permutation after the Joe's joke!
Input
The input parameter le contains a single line with a single string-the Joey's permutation without spaces.
The Joey's permutation had at least 1 and at most 50 numbers.
Output
Write a line to the output parameter le with the restored permutation. Don't forget the spaces!
If there are several possible original permutations, write any one of them.
Sample input and output
Joke. in

4111109876532

Joke. out

4 1 11 10 9 8 7 6 5 3 2

 

Link: http://codeforces.com/gym/100553/attachments/download/2885/20142015-acmicpc-northeastern-european-regional-contest-neerc-14-en.pdf

 

Enter a row of numbers. All numbers are separated by no space. These numbers are in 1-N groups. the string length is at least 1 and at most 50. Output the numbers in the row and separate them with spaces.

 

This is a classic dfs search. The current status is the I character of the string. If this number is not marked, search for dfs (I + 1, t + 1); if I + 1 <len, then combine it with the character following it into a number. If the number does not exceed n and is not marked, search for dfs (I + 2, t + 1). If none of them match, return backtracing. Note that if the dfs search does not meet the requirements, remember to restore the mark status of the number. When I = len, it indicates that one of the cases has been searched and may become abnormal, in this case, we need to use a for loop traversal to determine whether all numbers are marked.

 

# Include <iostream> # include <cstdio> # include <cstring> using namespace std; char s [55]; int flag [55]; int x [55]; int len, n; int gg; void dfs (int I, int t); int main () {freopen ("joke. in "," r ", stdin); freopen (" joke. out "," w ", stdout); int I; memset (s, 0, sizeof (s); memset (x, 0, sizeof (x )); memset (flag, 0, sizeof (flag); scanf ("% s", s); len = strlen (s); if (len <10) // optimized, {n = len; for (I = 0; I <n-1; I ++) printf ("% c", s [I]); printf ("% c \ n", s [I]);} else {n = (len-9)/2 + 9; gg = 0; dfs );} return 0;} void dfs (int I, int t) {if (I = len) {int sign = 1; for (int j = 1; j <= n; j ++) if (flag [j] = 0) {sign = 0; break;} if (sign) {for (int j = 0; j <n-1; j ++) printf ("% d", x [j]); printf ("% d \ n", x [n-1]); gg = 1;} return ;} if (gg = 1) return; if (flag [s [I]-48] = 0) {flag [s [I]-48] = 1; x [t] = s [I]-48; dfs (I + 1, t + 1); if (gg) return; flag [s [I]-48] = 0;} if (I + 1) <len & (s [I]-48) * 10 + (s [I + 1]-48) <= n & flag [(s [I]-48) * 10 + (s [I + 1]-48)] = 0) {flag [(s [I]-48) * 10 + (s [I + 1]-48)] = 1; x [t] = (s [I]-48) * 10 + (s [I + 1]-48); dfs (I + 2, t + 1); if (gg) return; flag [(s [I]-48) * 10 + (s [I + 1]-48)] = 0;} return ;}