delete pics to save space

1.4035.cpp

@@ -0,0 +1,42 @@
+#include<cstdio>
+#include<cmath>
+#include<algorithm>
+using namespace std;
+#define For(i,a,b) for(int i=(a);i<=(b);++i)
+const int maxn=15;
+const double eps=1e-8;
+int n;
+double a[maxn][maxn],b[maxn],c[maxn][maxn];
+int main()
+{
+#ifdef local
+	freopen("pro.in","r",stdin);
+#endif
+	scanf("%d",&n);
+	For(i,1,n+1) For(j,1,n) scanf("%lf",&a[i][j]);
+	For(i,1,n) For(j,1,n)
+	{
+		c[i][j]=2*(a[i][j]-a[i+1][j]);
+		b[i]+=a[i][j]*a[i][j]-a[i+1][j]*a[i+1][j];
+	}
+	For(i,1,n)
+	{
+		For(j,i,n)
+			if(fabs(c[j][i])>eps)
+			{
+				For(k,1,n) swap(c[i][k],c[j][k]);
+				swap(b[i],b[j]);
+				break;
+			}
+		double d=c[i][i];
+		For(j,i,n) c[i][j]/=d; b[i]/=d;
+		For(j,1,n)
+		{
+			if(i==j) continue;
+			double r=c[j][i];
+			For(k,1,n) c[j][k]-=r*c[i][k]; b[j]-=r*b[i];
+		}
+	}
+	For(i,1,n) printf("%.3lf ",b[i]); printf("\n");
+	return 0;
+}