diff options
Diffstat (limited to 'c')
| -rw-r--r-- | c/206-concealed_square.c | 41 |
1 files changed, 41 insertions, 0 deletions
diff --git a/c/206-concealed_square.c b/c/206-concealed_square.c new file mode 100644 index 0000000..4b94486 --- /dev/null +++ b/c/206-concealed_square.c @@ -0,0 +1,41 @@ +/* +* Concealed Square +* Problem 206 +* +* Find the unique positive integer whose square has the form 1_2_3_4_5_6_7_8_9_0, where each “_” is a single digit. +*/ + +#include <stdio.h> +#include <math.h> +#include <stdbool.h> + +typedef long long unsigned int t_llu; + +int main(void) +{ + t_llu n = (t_llu)floor(sqrt(1020304050607080900)) - 1000; + + while (true) + { + t_llu s = n * n; + + if ((s % 10llu) / 1llu == 0 && + (s % 1000llu) / 100llu == 9 && + (s % 100000llu) / 10000llu == 8 && + (s % 10000000llu) / 1000000llu == 7 && + (s % 1000000000llu) / 100000000llu == 6 && + (s % 100000000000llu) / 10000000000llu == 5 && + (s % 10000000000000llu) / 1000000000000llu == 4 && + (s % 1000000000000000llu) / 100000000000000llu == 3 && + (s % 100000000000000000llu) / 10000000000000000llu == 2 && + (s % 10000000000000000000llu) / 1000000000000000000llu == 1) + { + printf("%llu\n", n); + printf("%llu\n", s); + break; + } + n++; + } + + return 0; +} |