#include <vector>
#include <cstdio>
const unsigned pvalue = 1e9 + 7;
inline bool is_mopadulo(unsigned long long v) {
return (v % pvalue) % 2 == 0;
}
int main() {
int n;
scanf("%d", &n);
std::vector<int> tab(n, 0);
for (int i = 0; i < n; ++i)
scanf("%d", &tab[i]);
std::vector<unsigned> mem(n+1, 0);
unsigned long long sum = 0;
for (size_t i = 0; i < n; ++i)
{
unsigned long long v = 0;
sum += tab[i];
if (is_mopadulo(sum))
v = 1;
unsigned long long sumt = sum;
for (size_t j = 0; j < i; ++j)
{
sumt -= tab[j];
if (is_mopadulo(sumt)) {
v += mem[j];
v %= pvalue;
}
}
mem[i] = v;
}
printf("%u\n", mem[n-1]);
return 0;
}
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 | #include <vector> #include <cstdio> const unsigned pvalue = 1e9 + 7; inline bool is_mopadulo(unsigned long long v) { return (v % pvalue) % 2 == 0; } int main() { int n; scanf("%d", &n); std::vector<int> tab(n, 0); for (int i = 0; i < n; ++i) scanf("%d", &tab[i]); std::vector<unsigned> mem(n+1, 0); unsigned long long sum = 0; for (size_t i = 0; i < n; ++i) { unsigned long long v = 0; sum += tab[i]; if (is_mopadulo(sum)) v = 1; unsigned long long sumt = sum; for (size_t j = 0; j < i; ++j) { sumt -= tab[j]; if (is_mopadulo(sumt)) { v += mem[j]; v %= pvalue; } } mem[i] = v; } printf("%u\n", mem[n-1]); return 0; } |
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