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e036.c
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e036.c
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#include <stdio.h>
int is_pal(int* x) {
int i, l = 0;
int is_ok = 1;
i = 0;
while (x[i++] != -1) {
l++;
}
for (i=0; i<l; i++) {
if (x[i]!=x[l-i-1]) is_ok = 0;
}
return is_ok;
}
void basis(int* x, int basis, int n) {
int i = 0;
while (n!=0) {
x[i++] = n % basis;
n /= basis;
x[i];
}
x[i]=-1;
}
int is_ok(int i) {
int basis10[11];
int basis2[21];
int j;
basis(basis2, 2, i);
basis(basis10, 10, i);
for (j=0; j<21; j++) {
if (basis2[j]==-1) break;
}
return is_pal(basis2) && is_pal(basis10);
}
int main(int argc, char* argv) {
int i;
long long sum = 0;
for (i=0; i<1000000; i++) {
if (is_ok(i)) sum += i;
}
printf("%lli\n", sum);
return 0;
}