{"id":6052,"date":"2023-10-08T00:01:06","date_gmt":"2023-10-08T07:01:06","guid":{"rendered":"https:\/\/c-for-dummies.com\/blog\/?p=6052"},"modified":"2023-10-07T11:29:14","modified_gmt":"2023-10-07T18:29:14","slug":"coin-flipping-madness-solution","status":"publish","type":"post","link":"https:\/\/c-for-dummies.com\/blog\/?p=6052","title":{"rendered":"Coin Flipping Madness – Solution"},"content":{"rendered":"

I hope you didn’t “flip out” over this month’s Exercise<\/a>. Flipping a coin can be done by hand or by using a computer. Using a computer is easier because it can be programmed to record each flip and it saves you hand muscle molecules for flipping and the chore of writing down the results.
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\nFlipping requires a simple expression in C: rand()%2<\/code><\/p>\n

But first, use the srand()<\/em> function to seed the randomizer: srand( (unsigned)time(NULL) )<\/code> This step ensures that the numbers aren’t identical each time you run the program.<\/p>\n

One hundred sets of 100 flips requires nested loops. Further, the flip totals for each run must be recorded. To meet this end, I use two arrays in my solution, heads[]<\/code> and tails[]<\/code>. Flips are tallied within the nested loop by using variables t<\/code> and h<\/code> for heads and tails. Here is the nested loop:<\/p>\n

\r\n    \/* 100 sets of 100 flips *\/<\/span>\r\n    for( x=0; x<iterations; x++ )\r\n    {\r\n        \/* process 100 flips *\/<\/span>\r\n        for( y=t=h=0; y<iterations; y++ )\r\n        {\r\n            if( rand()%2 )\r\n                t++;    \/* odd is \"tails\" *\/<\/span>\r\n            else\r\n                h++;    \/* even is \"heads\" *\/<\/span>\r\n        }\r\n        \/* output this round's results *\/<\/span>\r\n        printf(\"Set %3d: %2d Heads, %2d Tails\\n\",x+1,h,t);\r\n        \/* store the data *\/<\/span>\r\n        heads[x] = h;\r\n        tails[x] = t;\r\n    }<\/pre>\n
I set constant int<\/em> value iterations<\/code> equal to 100. This constant allows me to use the value 100 and potentially change it later without having to hunt and sift through the code.<\/p>\n
The outer for<\/em> loop spins 100 times. It outputs the results for each set and stores the results in arrays heads[]<\/code> and tails[]<\/code>.<\/p>\n
The inner for<\/em> loop flips the coins. Variable y<\/code> is the looping variable, but variables h<\/code> and t<\/code> are also initialized in the for<\/em> loop statement. An if-else<\/em> structure tallies the heads (zero) and tails (one) flips.<\/p>\n
The second part of the challenge is to interpret and output the results. Originally I wrote separate for<\/em> loops for each item requested:<\/p>\n