Submission #20874

#	Time	Username	Problem	Language	Result	Execution time	Memory
20874		gs14004	돌 옮기기 (GA7_stone)	C++11	100 / 100	96 ms	5316 KiB

stone

#include <bits/stdc++.h>
using namespace std;
typedef long long lint;
typedef long double llf;
typedef pair<lint, lint> pi;
const int mod = 1e9 + 7;

string s, t;
int l, n, fail[400005];

int main(){
	cin >> l >> n;
	for(int i=0; i<2*n; i++){
		char t[5];
		scanf("%*d %s",t);
		s.push_back(*t);
	}
	string t = s + s;
	for(auto &i : s) i = 'W' + 'B' - i;
	int p = 0, ans = 1e9;
	for(int i=1; i<s.size(); i++){
		while(p > 0 && s[i] != s[p]) p = fail[p];
		if(s[i] == s[p]) p++;
		fail[i+1] = p;
	}
	p = 0;
	for(int i=0; i<t.size(); i++){
		while(p > 0 && t[i] != s[p]) p = fail[p];
		if(t[i] == s[p]) p++;
		if(p == s.size()){
			ans = min({ans, i+1-2*n, 4*n-i-1});
		}
	}
	if(ans > 1e8){
		puts("-1");
		return 0;
	}
	cout << 1ll * ans * l;
}

Compilation message (stderr)

stone.cpp: In function 'int main()':
stone.cpp:21:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i=1; i<s.size(); i++){
                ^
stone.cpp:27:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i=0; i<t.size(); i++){
                ^
stone.cpp:30:8: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   if(p == s.size()){
        ^
stone.cpp:15:20: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%*d %s",t);
                    ^

• Subtask 1: 6 / 6
• Subtask 2: 11 / 11
• Subtask 3: 16 / 16
• Subtask 4: 23 / 23
• Subtask 5: 44 / 44