add jumpstep and allsort solution

Author: watercolor

allrange.c

@@ -0,0 +1,39 @@
+//全排列的递归实现
+#include <stdio.h>
+#include <string.h>
+void Swap(char *a, char *b)
+{
+    char t = *a;
+    *a = *b;
+    *b = t;
+}
+//k表示当前选取到第几个数,m表示共有多少数.
+void AllRange(char *pszStr, int k, int m)
+{
+    int i;
+    if (k == m)
+    {
+	static int s_i = 1;
+	printf("  第%3d个排列\t%s\n", s_i++, pszStr);
+    }
+    else
+    {
+	for (i = k; i <= m; i++) //第i个数分别与它后面的数字交换就能得到新的排列
+	{
+	    Swap(pszStr + k, pszStr + i);
+	    AllRange(pszStr, k + 1, m);
+	    Swap(pszStr + k, pszStr + i);
+	}
+    }
+}
+void Foo(char *pszStr)
+{
+    AllRange(pszStr, 0, strlen(pszStr) - 1);
+}
+int main()
+{
+    char szTextStr[] = "1234";
+    printf("%s 's all sort list below:\n", szTextStr);
+    Foo(szTextStr);
+    return 0;
+}

jumpsteps.c

@@ -0,0 +1,36 @@
+//全排列的递归实现
+#include <stdio.h>
+#include <string.h>
+/*一个人上台阶可以一次上1个，2个，或者3个，问这个人上n层的台阶，总共有几种走法？打印出走法*/
+/* 这是最笨也是最简单的解法 */
+
+static int eachsteps[] = {1,2,3};   /*store what step we can choose */
+static int step_type_no = sizeof(eachsteps) / sizeof(eachsteps[0]); /* store choose number */
+
+int jump_steps(int stepnum) {
+    static int walkstep[100];       /* store walk choice*/
+    static int walkstep_idx = 0;    /* store walk step */
+    int i;
+    int walk_no = 0;
+    if(stepnum == 0) {
+        /* print step choice */
+        for (i = 0; walkstep[i] != 0; i++)
+            printf("%d ", walkstep[i]);
+        printf("\n");
+
+        return 1;
+    }
+    for (i = 0; i < step_type_no; i++) {
+        walkstep[walkstep_idx++] = eachsteps[i];  /* remember this step choice in walkstep */
+        if(stepnum - eachsteps[i] >= 0)
+            walk_no += jump_steps(stepnum - eachsteps[i]);
+        walkstep[walkstep_idx--] = 0;             /* pop element */
+    }
+    return walk_no;
+}
+
+int test_jump_steps(int argc, const char *argv[])
+{
+    printf("number is %d", jump_steps(5));
+    return 0;
+}