题解 | #星际穿越#javascript:void(0);

一元二次方程求解

#include<stdio.h>
#include<math.h>

int main()
{
    long long h;
    scanf("%lld", &h);
    long long ans = (-1 + (long long)sqrt(1+4*h))/2;
    printf("%lld\n", ans);
    return 0;
}