#include<bits/stdc++.h> using namespace std; int main() { int a,b,c,s,p; cin>>a>>b>>c>>p; p=(a+b+c)/2; s=p*(p-a)(p-b)(p-c); cout<<sqrt(s); return 0; }

思路

公式都给你了。

code

#include<bits/stdc++.h>
using namespace std;
int a,b,c;
int main(){
	cin>>a>>b>>c;
	double p=(a+b+c)*0.5;
	printf("%.2f",sqrt(p*(p-a)*(p-b)*(p-c)));
	return 0;
}

shishang nb #include<bits/stdc++.h> using namespace std; int main() { double a,b,c,p,s; cin>>a>>b>>c; p=(a+b+c)/2.00; s=p*(p-a)(p-b)(p-c); cout<<fixed<<setprecision(2)<<sqrt(s); return 0; }

#include<bits/stdc++.h> using namespace std; int main() { double a,b,c,s,p; cin>>a>>b>>c; p=(a+b+c)/2; s=p*(p-a)(p-b)(p-c); if(a+b>c&&a+c>b&&b+c>a) { cout<<fixed<<setprecision(2)<<sqrt(s)<<endl; } return 0; }

```

```
#include<bits/stdc++.h>
using namespace std;
double a,b,c,p,ans;
int main()
{
	cin>>a>>b>>c;
	p=(a+b+c)/2;
	ans=sqrt(p*(p-a)*(p-b)*(p-c));
	printf("%.2lf",ans);
	return 0;
}
```

#include<bits/stdc++.h> using namespace std; int main() { double a,b,c,p,s; cin>>a>>b>>c; p=(a+b+c)/2.00; s=sqrt (p*(p-a)(p-b)(p-c)); cout<<fixed<<setprecision(2)<<s; }

#include<bits/stdc++.h> using namespace std; int main() { int a,b,c,p,s; cin>>a>>b>>c; p=(a+b+c)/2; s=p*(p-a)(p-b)(p-c); cout<<fixed<<setprecision(2)<<sqrt(s); return 0; }

#include<bits/stdc++.h> using namespace std; int main() { double a,b,c,d; cin>>a>>b>>c; d=(a+b+c)/2; cout<<fixed<<setprecision(2)<<sqrt(d*(d-a)(d-b)(d-c))<<endl; return 0; }

#include<bits/stdc++.h> using namespace std; int main() { double a,b,c,p,s; cin>>a>>b>>c; p=(a+b+c)/2; s=sqrt (p*(p-a)(p-b)(p-c)); cout<<fixed<<setprecision(2)<<s; }

#include <stdio.h>#include<stdlib.h>#include<math.h>int main(){ double a, b, c,area,s,max,min; scanf("%lf%lf%lf", &a, &b, &c); if ((a + b > c && a + c > b && b + c > a) && (a > b - c && b > a - c && c > a - b)) { s = (a + b + c) / 2; area = sqrt(s * (s - a) * (s - b) * (s - c)); printf("%.2lf\n", area); } else { if (a > b) max = a, min = b; else max = b, min = a; if (c > max) max = c; else max = max; if (c < min) min = c; else min = min; printf("%.2lf", max - min); } system("pause"); return 0;}

#include<bits/stdc++.h> using namespace std; int main() {double a,b,c,s,p,h; cin>>a>>b>>c; p=(a+b+c)/2; s=p*(p-a)(p-b)(p-c); h=sqrt(s); cout<<fixed<<setprecision(2)<<h; return 0; }

#include<bits/stdc++.h> using namespace std; int main() { double a,b,c,p,s; cin>>a>>b>>c; p=(a+b+c)/2.00; s=sqrt (p*(p-a)(p-b)(p-c)); cout<<fixed<<setprecision(2)<<s; }

#include<iostream> #include<iomanip> using namespace std; int main() { double a,b,c,d,e,f,g,z; cin>>a>>b; z=3.1415926; c=zbb; d=c2; e=2bz; f=ea; g=d+f; cout<<fixed<<setprecision(3)<<g; return 0; }