問題：A - 足し算 #include <cstdio> #include <iostream> using namespace std; #define REP(i, n) for (int i = 0; i < (n); ++i) int main(void) { int n, cnt = 0; scanf("%d", &n); REP(i, 4) { if (n & 1 << i) { cnt++; } } printf ("%d\n", cnt); REP(i, 4) { if (n & </iostream></cstdio>…