[置顶] 1-1/2+1/3-1/4+1/5 …… + 1/99 - 1/100的值

#define _CRT_SECURE_NO_WARNINGS 
#include <stdio.h>
#include <stdlib.h>
int main()
{
    float a=1.0;
    float sum=0.0;
    float n=0.0;
    float t=1.0;
    for(n=1;n<101;n++)
    { 
        a=t/n;
        t=-t;
        sum+=a;
    }
    printf("sum = %f\n",sum);
    system("pause");
    return 0;
}