洛谷_P1808 单词分类 （尚贤）

题目：https://www.luogu.com.cn/problem/P1808

代码1（暴搜）（90分）

#include <iostream>
#include <cstdio>
#include <algorithm>
#define INF 0x7fffffff
#define SIZE (int)10000 + 10
using namespace std;
string str[SIZE], temp;
int top;

int f1(const int &);
bool pan_duan(const string &);

int main() {
	freopen("cpp.in", "r", stdin);
	freopen("cpp.out", "w", stdout);
	int n;
	scanf("%d", &n);
	printf("%d\n", f1(n));
	return 0;
}

int f1(const int &n) {
	int ans = 0;
	for (int i = 1; i <= n; ++i) {
		cin >> temp;
		sort(temp.begin(), temp.end());
		if (top == 0 || !pan_duan(temp)) {
			str[++top] = temp;
			sort(str + 1, str + top + 1);
			++ans;
		}
	}
	return ans;
}
bool pan_duan(const string &x) {
	for (int i = 1; i <= top; ++i) {
		if (str[i] == x) {
			return true;
		}
	}
	return false;
}

继续改进（二分）（…90分）

#include <iostream>
#include <cstdio>
#include <algorithm>
#define INF 0x7fffffff
#define SIZE (int)10000 + 10
using namespace std;
string str[SIZE], temp;
int top;

int f1(const int &);
bool pan_duan(const int &, const int &, const string &);

int main() {
	freopen("cpp.in", "r", stdin);
	freopen("cpp.out", "w", stdout);
	int n;
	scanf("%d", &n);
	printf("%d\n", f1(n));
	return 0;
}

int f1(const int &n) {
	int ans = 0;
	for (int i = 1; i <= n; ++i) {
		cin >> temp;
		sort(temp.begin(), temp.end());
		if (top == 0 || !pan_duan(1, top, temp)) {
			str[++top] = temp;
			sort(str + 1, str + top + 1);
			++ans;
		}
	}
	return ans;
}
bool pan_duan(const int &l, const int &r, const string &x) {
	if (l > r) {
		return false;
	}
	int mid = (l + r) / 2;
	if (str[l] == x || str[r] == x || str[mid] == x) {
		return true;
	}
	return ((x > str[mid]) ? (pan_duan(mid + 1, r, x)) : (pan_duan(l, mid - 1, x)));
}

好吧，STL的map上阵（AC）

#include <iostream>
#include <cstdio>
#include <map>
#include <algorithm>
#include <string>
#define SIZE (int)1
using namespace std;
map<string, bool> m;

int f1(const int &);

int main() {
	freopen("cpp.in", "r", stdin);
	freopen("cpp.out", "w", stdout);
	int n;
	scanf("%d", &n);
	printf("%d\n", f1(n)) ;
	return 0;
}

int f1(const int &n) {
	int ans = 0;
	for (int i = 1; i <= n; ++i) {
		string temp;
		cin >> temp;
		sort(temp.begin(), temp.end());
		if (!m[temp]) {
			++ans;
			m[temp] = true;
		}
	}
	return ans;
}