PKU 3080 - Blue Jeans (KMP + 枚举)
题意
找出最长公共子序列。
思路
枚举第一个字符串的子串，然后对后面的KMP。
偷懒用了string，140+ms不忍直视
这题直接暴力都比用KMP快。。真是。。
代码
#include <cstdio>
#include <stack>
#include <set>
#include <iostream>
#include <string>
#include <vector>
#include <queue>
#include <functional>
#include <cstring>
#include <algorithm>
#include <cctype>
#include <string>
#include <map>
#include <cmath>
#define LL long long
#define SZ(x) (int)x.size()
#define Lowbit(x) ((x) & (-x))
#define MP(a, b) make_pair(a, b)
#define MS(arr, num) memset(arr, num, sizeof(arr))
#define PB push_back
#define F first
#define S second
#define ROP freopen("input.txt", "r", stdin);
#define MID(a, b) (a + ((b - a) >> 1))
#define LC rt << 1, l, mid
#define RC rt << 1|1, mid + 1, r
#define LRT rt << 1
#define RRT rt << 1|1
#define BitCount(x) __builtin_popcount(x)
const double PI = acos(-1.0);
const int INF = 0x3f3f3f3f;
using namespace std;
const int MAXN = 10000 + 10;
const int MOD = 1e9 + 7;
const int dir[][2] = { {-1, 0}, {1, 0}, {0, -1}, {0, 1} };
typedef pair<int, int> pii;
typedef vector<int>::iterator viti;
typedef vector<pii>::iterator vitii;
int f[15][100];
string str[15];
void GetFail(int r)
{
f[r][0] = f[r][1] = 0;
int m = SZ(str[r]);
for (int i = 1; i < m; i++)
{
int j = f[r][i];
while (j && str[r][j] != str[r][i]) j = f[r][j];
f[r][i + 1] = (str[r][j] == str[r][i] ? j + 1 : 0);
}
}
bool KMP(string P, int r)
{
int m = SZ(str[r]), n = SZ(P);
int j = 0;
for (int i = 0; i < m; i++)
{
while (j && P[j] != str[r][i]) j = f[r][j];
if (P[j] == str[r][i]) j++;
if (j == n) return true;
}
return false;
}
int main()
{
//ROP;
ios::sync_with_stdio(0);
int T, i, j, n, k;
cin >> T;
string tmp, sub;
while (T--)
{
bool flag = false;
cin >> n;
for (i = 0; i < n; i++)
{
cin >> tmp;
str[i] = tmp;
}
string ans;
for (i = 0; i < n; i++) GetFail(i);
for (i = 0; i < SZ(str[0]); i++)
for (j = 3; j + i - 1 < SZ(str[0]); j++)
{
sub = str[0].substr(i, j);
for (k = 1; k < n; k++)
if (!KMP(sub, k)) break;
if (k == n)
{
flag = true;
if (ans.size() < sub.size()) ans = sub;
else if (ans.size() == sub.size()) ans = min(ans, sub);
}
}
if (flag) cout << ans << endl;
else cout << "no significant commonalities" << endl;
}
return 0;
}
#include <cstdio>
#include <stack>
#include <set>
#include <iostream>
#include <string>
#include <vector>
#include <queue>
#include <functional>
#include <cstring>
#include <algorithm>
#include <cctype>
#include <string>
#include <map>
#include <cmath>
#define LL long long
#define SZ(x) (int)x.size()
#define Lowbit(x) ((x) & (-x))
#define MP(a, b) make_pair(a, b)
#define MS(arr, num) memset(arr, num, sizeof(arr))
#define PB push_back
#define F first
#define S second
#define ROP freopen("input.txt", "r", stdin);
#define MID(a, b) (a + ((b - a) >> 1))
#define LC rt << 1, l, mid
#define RC rt << 1|1, mid + 1, r
#define LRT rt << 1
#define RRT rt << 1|1
#define BitCount(x) __builtin_popcount(x)
const double PI = acos(-1.0);
const int INF = 0x3f3f3f3f;
using namespace std;
const int MAXN = 10000 + 10;
const int MOD = 1e9 + 7;
const int dir[][2] = { {-1, 0}, {1, 0}, {0, -1}, {0, 1} };
typedef pair<int, int> pii;
typedef vector<int>::iterator viti;
typedef vector<pii>::iterator vitii;
int f[15][100];
string str[15];
int main()
{
// ROP;
ios::sync_with_stdio(0);
int T, i, j, n, k;
cin >> T;
string tmp, sub;
while (T--)
{
bool flag = false;
cin >> n;
for (i = 0; i < n; i++)
{
cin >> tmp;
str[i] = tmp;
}
string ans;
//for (i = 0; i < n; i++) GetFail(i);
for (i = 0; i < SZ(str[0]); i++)
for (j = 3; j + i - 1 < SZ(str[0]); j++)
{
sub = str[0].substr(i, j);
for (k = 1; k < n; k++)
if (str[k].find(sub) == string::npos) break;
if (k == n)
{
flag = true;
if (ans.size() < sub.size()) ans = sub;
else if (ans.size() == sub.size()) ans = min(ans, sub);
}
}
if (flag) cout << ans << endl;
else cout << "no significant commonalities" << endl;
}
return 0;
}