add min-stack.c

Author: lightmen

min-stack.c

@@ -0,0 +1,42 @@
+typedef struct {
+    int *data;
+    int *min;
+    int top_data;
+    int top_min;
+} MinStack;
+
+void minStackCreate(MinStack *stack, int maxSize) {
+    stack->data = (int *)malloc(sizeof(int) * maxSize);
+    stack->min = (int *)malloc(sizeof(int) * maxSize);
+    
+    stack->top_data = -1;
+    stack->top_min = -1;
+}
+
+void minStackPush(MinStack *stack, int element) {
+    stack->data[++stack->top_data] = element;
+    
+    if(stack->top_min == -1 || element <= stack->min[stack->top_min]){
+        stack->min[++stack->top_min] = element;
+    }
+}
+
+void minStackPop(MinStack *stack) {
+    int top = minStackTop(stack);
+    if(top <= minStackGetMin(stack))
+        stack->top_min--;
+
+    stack->top_data--;
+}
+
+int minStackTop(MinStack *stack) {
+    return stack->data[stack->top_data];
+}
+
+int minStackGetMin(MinStack *stack) {
+    return stack->min[stack->top_min];
+}
+
+void minStackDestroy(MinStack *stack) {
+  
+}