自己写的。C语言。题解 | #自守数#

#include<stdio.h>
int main() {
    int n, i, j, square, count = 0;
    scanf("%d", &n);
    for (i = 0; i <= n; i++) {
        j = i;
        square = i * i;
        while (j > 0) {
            if (j % 10 != square % 10) {
                break;
            }
            j = j / 10;
            square = square / 10;
        }
        if (j == 0) {
            count++;
        }
    }
    printf("%d\n", count);
    return 0;
}