long long数组开在main内出现无法输入的情况

Question

以下是可以正常运行的C++代码程序：

#include<iostream>
#include<cstring>
const int maxn = 1510;
long long minnum[maxn][maxn];
using namespace std;
int main() {
    int n;
    cin>>n;
    for(int i = 0; i < n; i++)
        for(int j = 0; j <= i; j++)
            cin>>minnum[i][j];
    for(int i = n-2; i >= 0; i--)
        for(int j = 0; j <= i; j++)
            if(minnum[i+1][j] < minnum[i+1][j+1])
                minnum[i][j] = minnum[i][j] + minnum[i+1][j];
            else minnum[i][j] = minnum[i][j] + minnum[i+1][j+1];
    cout<<minnum[0][0];
    return 0;
}    

但是将long long minnum[maxn][maxn]开在main函数内，并加一句”memset(minnum, 0, sizeof(minnum));"在Windows下运行，会出现无法输入的情况，这是为什么？

#include<iostream>
#include<cstring>
const int maxn = 1510;
using namespace std;
int main() {
    long long minnum[maxn][maxn];
    memset(minnum, 0, sizeof(minnum));
    int n;
    cin>>n;
    for(int i = 0; i < n; i++)
        for(int j = 0; j <= i; j++)
            cin>>minnum[i][j];
    for(int i = n-2; i >= 0; i--)
        for(int j = 0; j <= i; j++)
            if(minnum[i+1][j] < minnum[i+1][j+1])
                minnum[i][j] = minnum[i][j] + minnum[i+1][j];
            else minnum[i][j] = minnum[i][j] + minnum[i+1][j+1];
    cout<<minnum[0][0];
    return 0;
}    

Answer 1

临时变量太大了。
放在main函数里，long long minnum[maxn][maxn]数组就是个局部变量，局部变量没有这么大空间给你，所以失败了
放在main函数之上，就是全局变量，全局变量空间大，能够分配给你这个空间，所以OK