Pop 最小值的栈

popmin.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define ERROR_DATA -999999

typedef struct {
    int *pData;
    int length;
    int top;
} Heap_t;

void init(int *pData, int length);
void push(Heap_t *pHeap, int value);
int pop(Heap_t *pHeap);
int pop_min(Heap_t *pHeap);

void push(Heap_t *pHeap, int value){
    if (pHeap->top >= pHeap->length){
        fprintf(stderr, "Stack overflow");
        return;
    }
    pHeap->pData[pHeap->top] = value;
    pHeap->top++;
}

int pop(Heap_t *pHeap){
    int result;
    if (pHeap->top == 0){
        fprintf(stderr, "Stack underflow");
        return ERROR_DATA;
    }
    result = pHeap->pData[pHeap->top];
    pHeap->top--;
    return result;
}

int pop_min(Heap_t *pHeap){
    int i;
    int minValue = 999999;
    int minIndex;
    if (pHeap->top == 0){
        fprintf(stderr, "Stack underflow");
        return ERROR_DATA;
    }
    for (i=0; i<pHeap->top; i++){
        if (pHeap->pData[i] < minValue){
            minValue = pHeap->pData[i];
            minIndex = i;
        }
    }
    memmove(pHeap->pData + minIndex, pHeap->pData + minIndex + 1, (pHeap->top - minIndex) * sizeof(int));
    pHeap->top--;
    return minValue;
}