memset, fill 对bool，int 赋值的效率

memset对bool型变量赋false比对int型变量赋0快了10倍

fill对bool型变量赋false和对int型变量赋0效率一样

fill对int型变量赋0比memset对int型变量赋0慢了10倍

归结来说，以后要赋变量false的初值时，应该用bool型变量，用memset赋

#include <cstdio>
#include <cstring>
#include <ctime>
#include <algorithm>
using namespace std;

int d[];
bool d2[];
int has_train[][][];
bool has_train2[][][];

int main()
{
    clock_t start, finish;
    start = clock();
    int k = ;
    while(k--)
    {
        memset(d, , sizeof(d));
    }
    finish = clock();
    printf("%f\n", (double)(finish - start) / CLOCKS_PER_SEC);
    start = clock();
    k = ;
    while(k--)
    {
        memset(d2, false, sizeof(d2));
    }
    finish = clock();
    printf("%f\n", (double)(finish - start) / CLOCKS_PER_SEC);
    start = clock();
    k = ;
    while(k--)
    {
        memset(has_train, , sizeof(has_train));
    }
    finish = clock();
    printf("%f\n", (double)(finish - start) / CLOCKS_PER_SEC);
    start = clock();
    k = ;
    while(k--)
    {
        memset(has_train2, false, sizeof(has_train2));
    }
    finish = clock();
    printf("%f\n", (double)(finish - start) / CLOCKS_PER_SEC);

    start = clock();
    k = ;
    while(k--)
    {
        fill(d, d+, );
    }
    finish = clock();
    printf("%f\n", (double)(finish - start) / CLOCKS_PER_SEC);
    start = clock();
    k = ;
    while(k--)
    {
        fill(d2, d2+, false);
    }
    finish = clock();
    printf("%f\n", (double)(finish - start) / CLOCKS_PER_SEC);
    start = clock();
    k = ;
    while(k--)
    {
        fill(has_train[][], has_train[][]+, );
    }
    finish = clock();
    printf("%f\n", (double)(finish - start) / CLOCKS_PER_SEC);
    start = clock();
    k = ;
    while(k--)
    {
        fill(has_train2[][], has_train2[][]+, false);
    }
    finish = clock();
    printf("%f\n", (double)(finish - start) / CLOCKS_PER_SEC);
    return ;
}

//最后我尝试了直接对int型和bool型数组赋值而不使用memset和fill，发现效率和memset对int 型数组赋值0效率是一样的。