#include <cstdio>
#include <iostream>
#include <queue>
using namespace std;
const int maxn = 1002;

int m, n, ans = 0;
bool court[maxn][maxn], vis[maxn][maxn];
char c;
priority_queue<int> x;
priority_queue<int> y;

void dfs(int curY, int curX) {
	vis[curY][curX] = true;
	x.push(curX);
	y.push(curY);
	if(!vis[curY + 1][curX] && court[curY + 1][curX])	//not visited and true
		dfs(curY + 1, curX);
	if(!vis[curY - 1][curX] && court[curY - 1][curX])
		dfs(curY - 1, curX);
	if(!vis[curY][curX + 1] && court[curY][curX + 1])
		dfs(curY, curX + 1);
	if(!vis[curY][curX - 1] && court[curY][curX - 1])
		dfs(curY, curX - 1);
	return;
}

bool isShip() {
	int lastX = x.top(), lastY = y.top();
	x.pop();
	y.pop();
	bool first = true;
	for(int maxY = 0, cnt = 0; !x.empty(); x.pop() ) {	//cnt--recall maxY
		cnt++;
		if(lastX != x.top() ) {
			lastX = x.top();
			if(first) {
				first = false;
				maxY = cnt;
			}
			else {
				if(cnt != maxY)
					return false;
			}
			cnt = 0;
		}
		
	}
	first = true;
	for(int maxX = 0, cnt = 0; !y.empty(); y.pop() ) {	//cnt--recall maxY
		cnt++;
		if(lastY != y.top() ) {
			lastY = y.top();
			if(first) {
				first = false;
				maxX = cnt;
			}
			else {
				if(cnt != maxX)
					return false;
			}
			cnt = 0;
		}

	}
	return true;
}

int main() {
	//init
	scanf("%d%d", &n, &m);
	for(int i = 1; i <= n; i++)
		for(int j = 1; j <= m; j++) {
			cin >> c;
			if(c == '#')	//turn to bool
				court[i][j] = true;
			else
				court[i][j] = false;
		}
		
	for(int i = 1; i <= n; i++)
		for(int j = 1; j <= m; j++) 
			if(court[i][j] && !vis[i][j] ) {			//if true here
				dfs(i, j);
				if(isShip() )
					ans++;
			}
	if(!ans)
		printf("Bad placement.");
	else
		printf("There are %d ships.", ans);
	return 0;
}

在最后的时候，我的判定是：若ans为0，则输出“Bad-”，然而题意申明：一旦有无效船只就输出“Bad-”。也就是说，我的代码里，无论有没有无效船只，只要有有效船就输出答案，与题意违背，但是这段代码却只带来了1个WA而且还是特判