牛客小白月赛86（真小白）

A.水盐平衡

#include <bits/stdc++.h>
#define IO ios::sync_with_stdio(false);cin.tie(0);cout.tie(0);
using namespace std;
    
void solve() {
    int a, b, c, d; cin >> a >> b >> c >> d;

    if (a * d < c * b) cout << "Y\n";
    else cout << "S\n";
}

int main()
{
    IO;
    int t; cin >> t;
    while (t--) {
        solve();
    }
    return 0;
}

B.水平考试

#include <bits/stdc++.h>
#define IO ios::sync_with_stdio(false);cin.tie(0);cout.tie(0);
using namespace std;
    
void solve() {
    string a, b; cin >> a >> b;
    for (auto& x : a) {
        if (!count(b.begin(), b.end(), x)) {
            cout << "0\n";
            return ;
        }
    }
    cout << "10\n";
}

int main()
{
    IO;
    int t; cin >> t;
    while (t--) {
        solve();
    }
    return 0;
}

D

#include <bits/stdc++.h>
#define IO ios::sync_with_stdio(false);cin.tie(0);cout.tie(0);
using namespace std;
const int N = 1005;

char arr[N][N];
int n, m, cnt, maxx, maxy, minx, miny;
int dirs[][2] = {{1, 0}, {0, 1}, {-1, 0}, {0, -1}};

bool isVild(int x, int y) {
    if (x >= 0 && x < n && y >= 0 && y < m && arr[x][y] == '.') {
        return true;
    }
    return false;
}

void dfs(int x, int y) {
    arr[x][y] = '*';
    cnt ++;
    maxx = max(maxx, x), maxy = max(maxy, y);
    minx = min(minx, x), miny = min(miny, y);

    for (int i = 0; i < 4; i++) {
        int dx = dirs[i][0] + x;
        int dy = dirs[i][1] + y;
        if (isVild(dx, dy)) {
            dfs(dx, dy);
        }
    }
}

bool check(int maxx, int maxy, int minx, int miny, int cnt) {
    return (maxx - minx + 1) * (maxy - miny + 1) == cnt;
}
int main()
{
    IO;
    cin >> n >> m;
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < m; j++) cin >> arr[i][j];
    }

    int ans = 0; 

    for (int i = 0; i < n; i++) {
        for (int j = 0; j < m; j++) {
            if (arr[i][j] == '.') {
                cnt = 0, maxx = maxy = 0, minx = miny = N;
                dfs(i, j);
                if (check(maxx, maxy, minx, miny, cnt)) ans ++;
            }
        }
    }
    return cout << ans << '\n', 0;
}