Image Service (Search) 10132 file fragmentation)

Question connection: 10132 file fragmentation

There are n files consisting of 0 and 1, each of which is randomly divided into two parts. Now all 2n fragments are given, and the original sequence must be found.

Solution: search for the right two ends. The shortest must match the longest.

#include <stdio.h>#include <string.h>#include <string>#include <algorithm>#include <iostream>using namespace std;const int N = 300;char str[N];string file[N];int vis[N], len, n;string order;bool cmp(const string &a, const string &b) {    return a.length() < b.length();}bool solved(int cur) {    if (cur >= n / 2)return true;    vis[cur] = 1;    int l = file[cur].length();    for (int i = n - 1; i >= 0; i--) {if (vis[i])   continue;if (l + file[i].length() > len)   return true;if (l + file[i].length() < len)   return false;string p, q;p = file[cur] + file[i];q = file[i] + file[cur];if (p == order || q == order) {    vis[i] = 1;    if (solved(cur + 1))return true;    vis[i] = 0;}    }    vis[cur] = 0;    return false;}int main() {    int cas, sum, max;    scanf("%d%*c%*c", &cas);    while (cas--) {sum = n = 0;memset(vis, 0, sizeof(vis));while (gets(str)) {    if (!str[0])break;    file[n] = str;    sum += file[n++].length();}sort(file, file + n, cmp);len = sum * 2 / n;vis[0] = 1;for (int i = n - 1; i >= 0; i--) {    vis[i] = 1;    order.clear();    order = file[0] + file[i];    if (solved(1))  break;    order.clear();    order = file[i] + file[0];    if (solved(1))  break;    vis[i] = 0;}cout << order << endl;if (cas)    cout << endl;    }    return 0;}