hdu 1583 DNA Assembly

/* Author: ACb0y Date: 2010-9-05 Type: force ProblemId: hdu 1583 DNA Assembly Result: 2919263 2010-09-05 10:02:43 Accepted 1583 281MS 272K 1079 B C++ ACb0y */ #include <iostream> #include <string> using namespace std; int n; int ans; int d[10]; int vis[10]; string str[10]; //字符串合并 string str_merge(string a, string b) { if (a == "") { return b; } int i; int flag = 0; int pos; int alen = a.length(); int blen = b.length(); for (i = 1; i <= alen; i++) { if (b.substr(0, i) == a.substr(alen - i, i)) { flag = 1; pos = i; } } if (flag) { return a + b.substr(pos, blen - pos); } else { return a + b; } } //回溯法求N！ void dfs(int pos) { int i; if (pos == n) { string temp = ""; for (i = 0; i < n; i++) { temp = str_merge(temp, str[d[i]]); } if (temp.length() < ans) { ans = temp.length(); } } else { for (i = 0; i < n; i++) if (!vis[i]) { d[pos] = i; vis[i] = 1; dfs(pos + 1); vis[i] = 0; } } } int main() { int i; #ifndef ONLINE_JUDGE freopen("1583.txt", "r", stdin); #endif while (cin >> n) { for (i = 0; i < n; i++) { cin >> str[i]; } memset(vis, 0, sizeof(vis)); ans = 10000; dfs(0); cout << ans << endl; } return 0; }