Submission #1215014

#	Time	Username	Problem	Language	Result	Execution time	Memory
1215014		nvc2k8	Lamps (JOI19_lamps)	C++20	100 / 100	60 ms	19948 KiB

lamp

#include <bits/stdc++.h>
#define TASK "kasdjkasdj"
#define INT_LIM (int) 2147483647
#define LL_LIM (long long) 9223372036854775807
#define endl '\n'
#define mp make_pair
#define pb push_back
#define fi first
#define se second
#define BIT(i,x) (((i)>>(x))&1)
#define FOR(i,a,b) for(int i = (a); i<=(b); i++)
#define FORD(i,a,b) for(int i = (a); i>=(b); i--)
#define ll long long
#define pii pair<int,int>
using namespace std;
///------------------------------------------///
void minimize(int &x, const int &y)
{
    if (x>y) x = y;
}
int n;
int a[1000005];
int b[1000005];

void inp()
{
    cin >> n;
    FOR(i, 1, n)
    {
        char x;
        cin >> x;
        if (x=='1') a[i] = 1;
    }
    FOR(i, 1, n)
    {
        char x;
        cin >> x;
        if (x=='1') b[i] = 1;
    }
}

int f[1000005][3];

void solve()
{
    f[1][2] = (a[1]!=b[1]);
    f[1][1] = (b[1]!=1)+1;
    f[1][0] = (b[1]!=0)+1;

    FOR(i, 2, n) FOR(s1, 0, 2)
    {
        f[i][s1] = INT_LIM;
        FOR(s2, 0, 2)
        {
            int t1 = a[i], t2 = a[i-1];
            if (s1<2) t1 = s1;
            if (s2<2) t2 = s2;
            t1 = (t1!=b[i]);
            t2 = (t2!=b[i-1]);
            int g = 0;
            if (t1==1 && t2==0) g = 1;

            if (s1==s2)
            {
                minimize(f[i][s1], f[i-1][s2]+g);
                continue;
            }
            if (s1<2) minimize(f[i][s1], f[i-1][s2]+1+g);
            else minimize(f[i][s1], f[i-1][s2]+g);
        }
//        cout << i << ' ' << s1 << ' ' << f[i][s1] << endl;
    }

    int ans = INT_LIM;
    minimize(ans, f[n][0]);
    minimize(ans, f[n][1]);
    minimize(ans, f[n][2]);
    cout << ans;
}

signed main()
{
    ///--------------------------///
    ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);
    if (fopen(TASK".INP","r")!=NULL)
    {
        freopen(TASK".INP","r",stdin);
        freopen(TASK".OUT","w",stdout);
    }
    ///--------------------------///

    int NTEST = 1;
    //cin >> NTEST;

    while (NTEST--)
    {
        inp();
        solve();
    }

    return 0;
}

///------------------------------------------///

Compilation message (stderr)

lamp.cpp: In function 'int main()':
lamp.cpp:87:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   87 |         freopen(TASK".INP","r",stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
lamp.cpp:88:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   88 |         freopen(TASK".OUT","w",stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 6 / 6
• Subtask 2: 41 / 41
• Subtask 3: 4 / 4
• Subtask 4: 49 / 49