题目链接：https://pintia.cn/problem-sets/994805148990160896/problems/994805155206119424
暴力，基本上不会超时，dfs加上一些剪枝
算法：dfs
#include<iostream>
#include<cstdio>
#include<string>
#include<cstring>
#include<algorithm>
#include<set>
#include<map>
#include<vector>
#define N 150
#define inf 0x3f3f3f
using namespace std;
int n;
int op[N][N];
int po[N][N];
string str[N];
string q[N];
int num[N];
int ans = 0;
int vis[N];
int re = inf;
int flagss = 0;
void dfs(int index,int u,string s) {
if (flagss == 1)
return;
if (s.size() == 0) {
re = min(re, index);
if (re == 0) {
flagss = 1;
}
return ;
}
for (int i = u; i <= ans; i++) {
set<char>p;
int ks[N];
int sd = 0;
for (int j = 0; j < s.size();j++) {
if (!p.count(s[j])) {
if (op[i][s[j]] == 0)
{
sd = 1;
break;
}
ks[s[j]] = 1;
p.insert(s[j]);
}
else {
if (ks[s[j]] + 1 > op[i][s[j]]) {
sd = 1;
break;
}
ks[s[j]]++;
}
}
if (sd == 1)
{
break;
}
string s1 = s;
int nu1 = str[num[i]].size();
int nu2 = s1.size();
for (string::iterator iter = q[i].begin(); iter != q[i].end();) {
if (s1.find_first_of(*iter) != -1)
{
s1.erase(s1.find_first_of(*iter), 1);
iter++;
}
else {
iter++;
}
}
int nu = nu1 - (nu2 - s1.size());
dfs(index + nu, u + 1, s1);
if (flagss == 1)
return;
}
}
int main() {
string s;
string s2;
cin >> s;
s2 = s;
memset(vis, 0, sizeof(vis));
scanf("%d", &n);
int flag = 0;
int flags = 0;
for (int i = 0; i < n; i++) {
cin >> str[i];
if (str[i] == s)
{
flags = 1;
}
if (flags == 1)
continue;
flag = 0;
for (int j = 0; j < str[i].size(); j++) {
if (s.find(str[i][j])!=string::npos) {
if (flag == 0) {
q[++ans] = "";
q[ans] += str[i][j];
po[ans][str[i][j]] = 1;
num[ans] = i;
flag = 1;
}
else {
q[ans] += str[i][j];
po[ans][str[i][j]]++;
}
}
}
}
if (flags == 1)
{
cout << "Yes " << flags-1 << endl;
return 0;
}
memset(op, 0, sizeof(op));
for (int i = ans; i >= 1; i--) {
for (int j = 0; j < s.size(); j++) {
if (q[i].find(s[j]) != string::npos) {
op[i][s[j]] = op[i + 1][s[j]] + po[i][s[j]];
}
else {
op[i][s[j]] = op[i + 1][s[j]];
}
}
}
dfs(0, 1,s);
if (re == inf)
{
for (int i = 1; i <= ans; i++) {
for (string::iterator iter = q[i].begin(); iter != q[i].end();) {
if (s2.find_first_of(*iter) != -1)
{
s2.erase(s2.find_first_of(*iter), 1);
iter++;
}
else {
iter++;
}
}
}
cout << "No " <<s2.size()<< endl;
}
else
cout <<"Yes " <<re<< endl;
return 0;
}