Adding solution to problem 1783...

1783.cpp

@@ -0,0 +1,129 @@
+#include <bits/stdc++.h>
+
+using namespace std;
+
+int main() {
+
+    int n;
+    scanf("%d", &n);
+
+    double xFirstOld, yFirstOld;
+    double xSecondOld, ySecondOld;
+    double xFirstNew, yFirstNew;
+    double xSecondNew, ySecondNew;
+
+    for (int i = 1; i <= n; i++) {
+
+        scanf("%lf%lf", &xFirstOld, &yFirstOld);
+        scanf("%lf%lf", &xSecondOld, &ySecondOld);
+        scanf("%lf%lf", &xFirstNew, &yFirstNew);
+        scanf("%lf%lf", &xSecondNew, &ySecondNew);
+
+        double xHole, yHole;
+
+        bool isFirst = false, isSecond = false;
+        bool xDef = false, yDef = false;
+
+        double dxFirst = xFirstNew - xFirstOld;
+        double dyFirst = yFirstNew - yFirstOld;
+
+        double aFirst, bFirst;
+
+        if (dxFirst == 0 && dyFirst == 0) {
+
+            yHole = (yFirstNew + yFirstOld) / 2;
+            yDef = true;
+
+            xHole = (xFirstNew + xFirstOld) / 2;
+            xDef = true;
+
+        } else if (dxFirst == 0) {
+
+            yHole = (yFirstNew + yFirstOld) / 2;
+            yDef = true;
+
+        } else if (dyFirst == 0) {
+
+            xHole = (xFirstNew + xFirstOld) / 2;
+            xDef = true;
+
+        } else {
+
+            aFirst = -(dxFirst / dyFirst);
+            double midX = (xFirstNew + xFirstOld) / 2;
+            double midY = (yFirstNew + yFirstOld) / 2;
+            bFirst = midY - aFirst * midX;
+            isFirst = true;
+
+        }
+
+        double dxSecond = xSecondNew - xSecondOld;
+        double dySecond = ySecondNew - ySecondOld;
+
+        double aSecond, bSecond;
+
+        if (dxSecond == 0 && dySecond == 0) {
+
+            yHole = (ySecondNew + ySecondOld) / 2;
+            yDef = true;
+
+            xHole = (xSecondNew + xSecondOld) / 2;
+            xDef = true;
+
+        } else if (dxSecond == 0) {
+
+            yHole = (ySecondNew + ySecondOld) / 2;
+            yDef = true;
+
+        } else if (dySecond == 0) {
+
+            xHole = (xSecondNew + xSecondOld) / 2;
+            xDef = true;
+
+        } else {
+
+            aSecond = -(dxSecond / dySecond);
+            double midX = (xSecondNew + xSecondOld) / 2;
+            double midY = (ySecondNew + ySecondOld) / 2;
+            bSecond = midY - aSecond * midX;
+            isSecond = true;
+
+        }
+
+        if (isFirst && isSecond) {
+
+            yHole = (aFirst*bSecond - aSecond*bFirst) / (aFirst - aSecond);
+            xHole = (yHole - bFirst) / aFirst;
+
+        } else if (isFirst) {
+
+            if (xDef) {
+
+                yHole = aFirst * xHole + bFirst;
+
+            } else if (yDef) {
+
+                xHole = (yHole - bFirst) / aFirst;
+
+            }
+
+        } else if (isSecond) {
+
+            if (xDef) {
+
+                yHole = aSecond * xHole + bSecond;
+
+            } else if (yDef) {
+
+                xHole = (yHole - bSecond) / aSecond;
+
+            }
+
+        }
+
+        printf("Caso #%d: %.2lf %.2lf\n", i, xHole, yHole);
+
+    }
+
+
+}