Unique path

Signed-off-by: begeekmyfriend <[email protected]>

062_unique_path/Makefile

@@ -0,0 +1,2 @@
+all:
+	gcc -O2 -o test unique_path.c

062_unique_path/unique_path.c

@@ -0,0 +1,57 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+static void valid_path_recursive(int col, int m, int row, int n, int *count)
+{
+    if (col == m - 1 && row == n - 1) {
+        (*count)++;
+    } else {
+        if (m > n) {
+            if (col < m - 1) {
+                valid_path(col + 1, m, row, n, count);
+            }
+            if (row < n - 1) {
+                valid_path(col, m, row + 1, n, count);
+            }
+        } else {
+            if (col < m - 1) {
+                valid_path(col + 1, m, row, n, count);
+            }
+            if (row < n - 1) {
+                valid_path(col, m, row + 1, n, count);
+            }
+        }
+    }
+}
+
+static int uniquePaths(int m, int n) {
+    //int count = 0;
+    //valid_path(0, m, 0, n, &count);
+    //return count;
+    int row, col;
+    int *grids = malloc(m * n * sizeof(int));
+    for (col = 0; col < m; col++) {
+        grids[col] = 1;
+    }
+    for (row = 0; row < n; row++) {
+        grids[row * m] = 1;
+    }
+    for (row = 1; row < n; row++) {
+        for (col = 1; col < m; col++) {
+            grids[row * m + col] = grids[row * m + col - 1] + grids[(row - 1) * m + col];
+        }
+    }
+    int result = grids[m * n - 1];
+    free(grids);
+    return result;
+}
+
+int main(int argc, char **argv)
+{
+    if (argc != 3) {
+        fprintf(stderr, "Usage: ./test m n\n");
+        exit(-1);
+    }
+    printf("%d\n", uniquePaths(atoi(argv[1]), atoi(argv[2])));
+    return 0;
+}

063_unique_paths_ii/Makefile

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+all:
+	gcc -O2 -o test unique_path.c

063_unique_paths_ii/unique_path.c

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+#include <stdio.h>
+#include <stdlib.h>
+
+static int uniquePathsWithObstacles(int** obstacleGrid, int obstacleGridRowSize, int obstacleGridColSize)
+{
+    int row, col;
+    int reset = 0;
+    for (row = 0; row < obstacleGridRowSize; row++) {
+        if (reset) {
+            obstacleGrid[row][0] = 1;
+        } else {
+            if (obstacleGrid[row][0] == 1) {
+                reset = 1;
+            }
+        }
+    }
+
+    reset = 0;
+    for (col = 0; col < obstacleGridColSize; col++) {
+        if (reset) {
+            obstacleGrid[0][col] = 1;
+        } else {
+            if (obstacleGrid[0][col] == 1) {
+                reset = 1;
+            }
+        }
+    }
+
+    for (row = 0; row < obstacleGridRowSize; row++) {
+        int *line = obstacleGrid[row];
+        for (col = 0; col < obstacleGridColSize; col++) {
+            line[col] ^= 1;
+        }
+    }
+
+    for (row = 1; row < obstacleGridRowSize; row++) {
+        int *last_line = obstacleGrid[row - 1];
+        int *line = obstacleGrid[row];
+        for (col = 1; col < obstacleGridColSize; col++) {
+            if (line[col] != 0) {
+                line[col] = line[col - 1] + last_line[col];
+            }
+        }
+    }
+
+    return obstacleGrid[obstacleGridRowSize - 1][obstacleGridColSize - 1];
+}
+
+int main(int argc, char **argv)
+{
+    if (argc < 3) {
+        fprintf(stderr, "Usage: ./test m n\n");
+        exit(-1);
+    }
+
+    int i, j, k = 3;
+    int row_size = atoi(argv[1]);
+    int col_size = atoi(argv[2]);
+    int **grids = malloc(row_size * sizeof(int *));
+    for (i = 0; i < row_size; i++) {
+        grids[i] = malloc(col_size * sizeof(int));
+        int *line = grids[i];
+        for (j = 0; j < col_size; j++) {
+            line[j] = atoi(argv[k++]);
+            printf("%d ", line[j]);
+        }
+        printf("\n");
+    }
+    printf("%d\n", uniquePathsWithObstacles(grids, row_size, col_size));
+    return 0;
+}