'commit'

TangDou/LanQiaoBei/LanQiao14GuoSai/4_1.cpp

@@ -0,0 +1,57 @@
+#include <bits/stdc++.h>
+using namespace std;
+
+const int N = 9;
+int g[N][N];
+
+int check(int r, int c, int x) {
+    // 同行，同列是不是存在同样的数字x
+    for (int i = 0; i < 9; i++)
+        if (g[r][i] == x || g[i][c] == x) return 0;
+
+    // 找出3X3的小方块开始行和开始列,也就是所在块左上角坐标
+    int row = r / 3 * 3;
+    int col = c / 3 * 3;
+    for (int i = 0; i < 3; i++)
+        for (int j = 0; j < 3; j++)
+            if (g[row + i][col + j] == x)
+                return 0;
+    return 1;
+}
+
+void dfs(int u) {
+    if (u == 81) {
+        for (int i = 0; i < 9; i++) {
+            for (int j = 0; j < 9; j++)
+                cout << g[i][j];
+            cout << endl;
+        }
+        exit(0);
+    }
+
+    int r = u / 9, c = u % 9;
+    if (g[r][c]) dfs(u + 1);
+    for (int x = 1; x <= 9; x++) {
+        if (check(r, c, x)) {
+            g[r][c] = x;
+            dfs(u + 1);
+            g[r][c] = 0;
+        }
+    }
+}
+
+int main() {
+#ifndef ONLINE_JUDGE
+    freopen("4.in", "r", stdin);
+#endif
+
+    for (int i = 0; i < 9; i++)
+        for (int j = 0; j < 9; j++) {
+            char x;
+            cin >> x;
+            if (x != '.') g[i][j] = x - '0';
+        }
+
+    dfs(0);
+    return 0;
+}