add problem 22 and test function

Author: supercoderhawk

C/1-50/22-Generate-Parentheses.c

@@ -0,0 +1,73 @@
+/*
+ * Given n pairs of parentheses, write a function to generate all combinations of well-formed parentheses.
+
+ * For example, given n = 3, a solution set is:
+ * [
+  "((()))",
+  "(()())",
+  "(())()",
+  "()(())",
+  "()()()"
+ * ]
+ * Created by supercoderx on 2017/8/10.
+ */
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+
+char** generateParenthesis(int n, int* returnSize) {
+    *returnSize = 0;
+    if(n<=0){
+        return NULL;
+    }
+    char **result = malloc(sizeof(char*)), *str = NULL;
+    int *curLeft = malloc(sizeof(int)),*allLeft=malloc(sizeof(int)),count;
+
+    for(int i = 0; i < 2*n;i++){
+        if(i == 0 ){
+            str = malloc(sizeof(char)*(2*n+1));
+            str[0] = '(';
+            str[2*n] = '\0';
+            result[0] = str;
+            curLeft[0] = 1;
+            allLeft[0] = n-1;
+            (*returnSize)++;
+        }else{
+            count = *returnSize;
+            for(int j = 0; j<count;j++){
+                if(curLeft[j]!=0 && allLeft[j]!=0){
+                    str = malloc(sizeof(char)*(2*n+1));
+                    str[2*n] = '\0';
+                    strcpy(str,result[j]);
+                    str[i] = '(';
+                    result[j][i] = ')';
+                    (*returnSize)++;
+                    curLeft = realloc(curLeft,sizeof(int)*(*returnSize));
+                    allLeft = realloc(allLeft,sizeof(int)*(*returnSize));
+                    result = realloc(result, sizeof(char*)*(*returnSize));
+                    curLeft[*returnSize-1] = curLeft[j]+1;
+                    allLeft[*returnSize-1] = allLeft[j]-1;
+                    result[*returnSize-1] = str;
+                    curLeft[j]--;
+                }else if(curLeft[j] == 0 && allLeft[j]>0){
+                    result[j][i] = '(';
+                    allLeft[j]--;
+                    curLeft[j]++;
+                }else if(allLeft[j]==0){
+                    result[j][i]=')';
+                    curLeft[j]--;
+                }
+            }
+        }
+    }
+    return result;
+}
+
+void testGenerateParenthesis(){
+    int count = 0;
+    char** result = generateParenthesis(3,&count);
+    for(int i = 0; i < count;i++){
+        printf("%s,",result[i]);
+    }
+
+}