Week 1 (21 September 2020) solution

Week 1 (21 September 2020)/Solution ( ADAMAT )/ADAMAT.cpp

@@ -0,0 +1,40 @@
+#include <bits/stdc++.h>
+using namespace std;
+
+int main() {
+	// your code goes here
+	int t,n,i,j,count;
+
+	scanf("%d",&t);
+	while(t--){
+
+	    scanf("%d",&n);
+	    count = 0;
+	    int a[n][n];
+	    for(i=0;i<n;i++)
+	        for(j=0;j<n;j++)
+	            scanf("%d" , &a[i][j]);
+	    bool boolean[n];
+	    for(j=0;j<n;j++)
+        {
+            if (a[0][j] == j+1)
+                boolean[j] = true;
+            else boolean[j] =false;
+        }
+
+        for (i=n-1;i>0;i--)
+        {
+            if(boolean[i] == false)
+            {
+                count++;
+                for(j=i; j>0; j--)
+                    boolean[j] = boolean[j]?false:true;
+            }
+        }
+
+        printf("%d\n", count);
+	}
+
+
+	return 0;
+}

Week 1 (21 September 2020)/Solution ( CHFNSWAP )/CHFNSWAP.cpp

@@ -0,0 +1,42 @@
+#include <bits/stdc++.h>
+using namespace std;
+
+long long pivot(long long n)
+{
+    long double nn = n;
+    return (long long)(((-2.0)+(sqrt(4.0+8*(n*n+n)))) / 4.0);       // from quad equation 2x^2 + 2x - (n^2 + n) = 0
+    // which comes from (x(x+1))/2= (n(n+1)/2)/2 and long long takes its floor value
+}
+
+long long nc2 (long long n){
+    return (n*n - n)/2;
+}
+
+int main() {
+	// your code goes here
+	long long t,n, sumn, x, ans;
+	scanf("%lld", &t);
+	while(t--){
+	    ans=0;
+	    scanf("%lld",&n);
+	    sumn = (n*(n+1))/2;
+
+	    if(sumn%2==1){         // not possible case sum=odd
+	        ans = 0;
+	    }
+	    else{
+	        x = pivot(n);
+	        ans += (n-x);
+
+	        if ( (x*x+x)*2 == (n*n + n) )
+	            ans += nc2(x) + nc2(n-x);
+            // if pivot actually exists before, then we can do all possible swaps in grp1 and all in grp2
+	    }
+
+	    printf("%lld\n", ans);
+
+	}
+
+
+	return 0;
+}

Week 1 (21 September 2020)/Solution ( CRDGAME )/CRDGAME.cpp

@@ -0,0 +1,46 @@
+#include <bits/stdc++.h>
+using namespace std;
+
+int calc(long long n){
+    int sum=0;
+    while(n!=0)
+    {
+        sum = sum + n%10;
+        n = n/10;
+    }
+    return sum;
+}
+
+int main() {
+	// your code goes here
+
+	int t,n,i, sa,sb, pointa, pointb;
+	long long a,b;
+	scanf("%d", &t);
+
+	while(t--){
+
+	    scanf("%d", &n);
+	    pointa=0; pointb=0;
+
+	    for(i=0;i<n;i++)
+	    {
+	        scanf("%lld %lld",&a,&b);
+	        sa = calc(a); sb=calc(b);
+
+	        if (sa==sb){
+	            pointa += 1;
+	            pointb += 1;
+	        }
+	        else sa>sb?pointa+=1:pointb+=1;
+	    }
+	    if(pointa > pointb)
+	        printf("0 %d\n", pointa);
+	   else if (pointa < pointb)
+	        printf("1 %d\n", pointb);
+	   else  printf("2 %d\n", pointb);
+
+	}
+
+	return 0;
+}