#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const int INF = 0x3f3f3f3f;
const int MAXN = 1e6 + 100;
const int MAXM = 3e3 + 10;
template < typename T > inline void read(T &x) {
	x = 0;
	T ff = 1, ch = getchar();
	while(!isdigit(ch)) {
		if(ch == '-') ff = -1;
		ch = getchar();
	}
	while(isdigit(ch)) {
		x = (x << 1) + (x << 3) + (ch ^ 48);
		ch = getchar();
	}
	x *= ff;
}
template < typename T > inline void write(T x) {
	if(x < 0) putchar('-'), x = -x;
	if(x > 9) write(x / 10);
	putchar(x % 10 + '0');
}
int T, n, m;
int vis[MAXN], dis[MAXN];
int lin[MAXN], tot = 0;
char ch;
struct edge {
	int y, v, next;
} e[MAXN];
inline void add(int xx, int yy, int vv) {
	e[++tot].y = yy;
	e[tot].v = vv;
	e[tot].next = lin[xx];
	lin[xx] = tot;
}
void Dijkstra() {
	memset(dis, 0x3f, sizeof(dis));
	memset(vis, false, sizeof(vis));
	priority_queue < pair < int, int > > q;
	dis[1] = 0;
	q.push(make_pair(0, 1));
	while(!q.empty()) {
		int x = q.top().second;
		q.pop();
		if(vis[x]) continue;
		vis[x] = true;
		for(int i = lin[x], y; i; i = e[i].next) {
			if(dis[y = e[i].y] > dis[x] + e[i].v) {
				dis[y] = dis[x] + e[i].v;
				if(!vis[y]) q.push(make_pair(-dis[y], y));
			}
		}
	}
}
int main() {
	read(T);
	while(T--) {
		read(n);
		read(m);
		memset(lin, 0, sizeof(lin));
		memset(e, 0, sizeof(e));
		tot = 0;
		for(int i = 1; i <= n; ++i) {
			for(int j = 1; j <= m; ++j) {
				ch = getchar();
				if(ch == '/') {
					add(((i - 1) * (m + 1) + j), i * (m + 1) + j + 1, 1);
					add(i * (m + 1) + j + 1, (i - 1) * (m + 1) + j, 1);
					add(i * (m + 1) + j, (i - 1) * (m + 1) + j + 1, 0);
					add((i - 1) * (m + 1) + j + 1, i * (m + 1) + j, 0);
				} else {
					add(((i - 1) * (m + 1) + j), i * (m + 1) + j + 1, 0);
					add(i * (m + 1) + j + 1, (i - 1) * (m + 1) + j, 0);
					add(i * (m + 1) + j, (i - 1) * (m + 1) + j + 1, 1);
					add((i - 1) * (m + 1) + j + 1, i * (m + 1) + j, 1);
				}
			}
			ch = getchar();
		}
		Dijkstra();
		if(dis[(n + 1) * (m + 1)] == INF) puts("NO SOLUTION");
		else write(dis[(n + 1) * (m + 1)]), puts("");
	}
	return 0;
}

C++ :

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const int INF = 0x3f3f3f3f;
const int MAXN = 1e6 + 100;
const int MAXM = 3e3 + 10;
template < typename T > inline void read(T &x) {
	x = 0;
	T ff = 1, ch = getchar();
	while(!isdigit(ch)) {
		if(ch == '-') ff = -1;
		ch = getchar();
	}
	while(isdigit(ch)) {
		x = (x << 1) + (x << 3) + (ch ^ 48);
		ch = getchar();
	}
	x *= ff;
}
template < typename T > inline void write(T x) {
	if(x < 0) putchar('-'), x = -x;
	if(x > 9) write(x / 10);
	putchar(x % 10 + '0');
}
int T, n, m;
int vis[MAXN], dis[MAXN];
int lin[MAXN], tot = 0;
char ch;
struct edge {
	int y, v, next;
} e[MAXN];
inline void add(int xx, int yy, int vv) {
	e[++tot].y = yy;
	e[tot].v = vv;
	e[tot].next = lin[xx];
	lin[xx] = tot;
}
void Dijkstra() {
	memset(dis, 0x3f, sizeof(dis));
	memset(vis, false, sizeof(vis));
	priority_queue < pair < int, int > > q;
	dis[1] = 0;
	q.push(make_pair(0, 1));
	while(!q.empty()) {
		int x = q.top().second;
		q.pop();
		if(vis[x]) continue;
		vis[x] = true;
		for(int i = lin[x], y; i; i = e[i].next) {
			if(dis[y = e[i].y] > dis[x] + e[i].v) {
				dis[y] = dis[x] + e[i].v;
				if(!vis[y]) q.push(make_pair(-dis[y], y));
			}
		}
	}
}
int main() {
	read(T);
	while(T--) {
		read(n);
		read(m);
		memset(lin, 0, sizeof(lin));
		memset(e, 0, sizeof(e));
		tot = 0;
		for(int i = 1; i <= n; ++i) {
			for(int j = 1; j <= m; ++j) {
				ch = getchar();
				if(ch == '/') {
					add(((i - 1) * (m + 1) + j), i * (m + 1) + j + 1, 1);
					add(i * (m + 1) + j + 1, (i - 1) * (m + 1) + j, 1);
					add(i * (m + 1) + j, (i - 1) * (m + 1) + j + 1, 0);
					add((i - 1) * (m + 1) + j + 1, i * (m + 1) + j, 0);
				} else {
					add(((i - 1) * (m + 1) + j), i * (m + 1) + j + 1, 0);
					add(i * (m + 1) + j + 1, (i - 1) * (m + 1) + j, 0);
					add(i * (m + 1) + j, (i - 1) * (m + 1) + j + 1, 1);
					add((i - 1) * (m + 1) + j + 1, i * (m + 1) + j, 1);
				}
			}
			ch = getchar();
		}
		Dijkstra();
		if(dis[(n + 1) * (m + 1)] == INF) puts("NO SOLUTION");
		else write(dis[(n + 1) * (m + 1)]), puts("");
	}
	return 0;
}

还是我来吧~

#include <iostream>
#include <cstring>
#include <deque>

using namespace std;

const int N = 510;

int n, m;
char g[N][N];
int dist[N][N];
bool st[N][N];

int bfs() {
    memset(st, false, sizeof st);
    memset(dist, 0x3f, sizeof dist);

    string s = "\\/\\/";
    int dx[] = {-1, -1, 1, 1}, dy[] = {-1, 1, 1, -1};
    int ix[] = {-1, -1, 0, 0}, iy[] = {-1, 0, 0, -1};

    deque<pair<int, int> > dq;
    dq.push_back({0, 0});
    dist[0][0] = 0;

    while (!dq.empty()) {
        auto t = dq.front();
        dq.pop_front();

        int x = t.first, y = t.second;

        if (x == n && y == m) return dist[x][y];

        if (st[x][y]) continue;
        st[x][y] = true;

        for (int i = 0; i < 4; i++) {
            int nx = x + dx[i], ny = y + dy[i];
            if (st[nx][ny]) continue;
            if (0 <= nx && nx <= n && 0 <= ny && ny <= m) {
            	
                int gx = x + ix[i], gy = y + iy[i];
             
                int w = (g[gx][gy] != s[i]);
                int d = dist[x][y] + w;
                if (d < dist[nx][ny]) {
                    dist[nx][ny] = d;
                    if (w) dq.push_back({nx, ny});
                    else dq.push_front({nx, ny});
                }
            }
        }
    }

    return -1;
}

int main() {
    int T;
    cin >> T;
    while (T--) {
        cin >> n >> m;
        
        for (int i = 0; i < n; i++)
            for (int j = 0; j < m; j++)
                cin >> g[i][j];

        if ((n + m) % 2) cout << "NO SOLUTION" << endl;
        else cout << bfs() << endl;
    }

    return 0;
}